JAPAN TESTS THE NUCLEAR TABOO

Abstract

This article examines whether recent changes in the security environment, including North Korea's nuclear test of October 2006, are driving Japan to consider the acquisition of its own nuclear deterrent. It argues that a combination of three factors have thus far sustained Japan's nuclear restraint: (1) national identity as a non-nuclear weapon state, (2) commitment to global nuclear nonproliferation and disarmament, and (3) realist security calculations. Partial changes in these factors have provoked in Japan a new round of debate about the nuclear question that can be grouped around three general options: (1) move toward a nuclear weapons option, (2) robust conventional defense and a stronger alliance with the United States, and (3) a more assertive non-nuclear diplomacy. The article concludes that the most likely Japanese course for the time being is to strengthen the alliance with the United States and improve conventional defense capabilities, including missile defense. Although the taboo about public discussions of the nuclear weapons option may be weakening, Japan will continue to forgo that option.

Keywords:

• Japan
• Nuclear weapons
• Nonproliferation regime
• Disarmament

Soon after the North Korean nuclear test on October 9, 2006, Prime Minister Abe Shinzō reassured the world that Japan would adhere to its three non-nuclear principles and not consider the option of developing its own nuclear deterrent. Abe was no doubt comforted by President George W. Bush's statement that “the United States has the will and the capability to meet the full range of its deterrent and security commitments to Japan.”1 But shortly after Abe reaffirmed Japan's commitment to forgo the nuclear option, his close political ally and policy affairs chairman of the ruling Liberal Democratic Party (LDP), Nakagawa Shōichi, declared on national television that “thinking about the surrounding circumstances, views that [Japan] should possess nuclear arms have naturally emerged. It is necessary to debate this thoroughly.” A few days later, Foreign Minister Asō Tarō echoed this view: “When a neighboring country has come to possess [nuclear weapons], it is important to debate this in various ways as one way of thinking.”2

When pressed by the opposition Democratic Party of Japan (DPJ) about a possible internal conflict in the government about this issue, Prime Minister Abe emphatically reconfirmed in the National Diet that the three non-nuclear principles will be preserved and that there will be absolutely no change in policy. He also went on to say that there would not be any debate about the possibility of possessing nuclear weapons within the cabinet, the government, or a formal organ of the ruling party. Nevertheless, he questioned whether it made sense to create such a huge controversy about references to the nuclear option in the context of debates about security. He stressed that there is a difference between discussing the nuclear issue and debating whether or not to possess nuclear weapons.3

The political and media controversy about these statements suggests two divergent interpretations. One is that despite the North Korean nuclear test, Japan remains so committed to nuclear restraint that even an open discussion of the nuclear option within government and political circles continues to be taboo enough to stir public controversy. But the other interpretation is that conservative political leaders like Nakagawa, Asō, and others are indeed chipping away at the nuclear taboo and preparing the national agenda for a fundamental reexamination of Japan's security policy that includes consideration of the nuclear option. And while Abe has held firm to Japan's non-nuclear weapons policy, he is unwilling to prevent a thorough discussion of Japanese options at the private sector level.

This article examines whether or not Japan may be approaching the “nuclear tipping point” because of changes in its security environment.4 In doing so, it first lays out the basic elements of Japan's policy regarding nuclear weapons and the underpinnings of this policy. It argues that a combination of three factors have worked together to sustain Japan's nuclear restraint: (1) national identity as a non-nuclear weapon state, (2) commitment to global nuclear nonproliferation and disarmament, and (3) realist security calculations. Second, the essay dissects the recent strategic debate in Japan regarding the nuclear question. It groups this debate around three general options: (1) move toward a nuclear weapons option, (2) robust conventional defense and a stronger alliance with the United States, and (3) a more assertive non-nuclear diplomacy. Finally, this article discusses the policy measures Japan is likely to take in the future. It argues that the most probable Japanese course for the time being is to strengthen the alliance with the United States and improve conventional defense capabilities, including missile defense. It concludes that although the taboo about public discussions of the nuclear weapons option may be weakening, Japan will continue to forgo that option.

Basic Parameters of Japan's Non-Nuclear Weapons Policy

At the core of Japan's “non-nuclear” policy are the three principles of “not possessing nuclear weapons, not producing nuclear weapons, and not permitting the introduction of nuclear weapons into Japan.” First enunciated in 1967 by the Satō government during parliamentary deliberations, these three non-nuclear principles have been endorsed by a unanimously approved Diet resolution and reaffirmed repeatedly by subsequent governments. The country's Atomic Energy Basic Law further prohibits the manufacture or possession of nuclear weapons. This basic law states, “The research, development, and utilization of atomic energy shall be limited to peaceful purposes, aimed at ensuring safety, and performed independently under democratic management.”5 Japan also signed the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 1970 and ratified the treaty in 1976. Under this treaty, it is obligated as a “non-nuclear weapon state, not to produce or acquire nuclear weapons.”6 Moreover, Japan signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in September 1996—the first non-nuclear weapon state to do so.

Article 9 of the postwar constitution constrains Japan's policy toward nuclear weapons but does not prohibit these weapons as such.7 In May 1957, Prime Minister Kishi Nobusuke (the maternal grandfather of current Prime Minister Abe) stated in the Diet that the constitution would permit the possession of minimally necessary nuclear weapons for self-defense purposes, but Japan forgoes such possession as a matter of policy. In 1978 and 1982, the Cabinet Legislative Bureau provided during parliamentary deliberations what has become the government's definitive interpretation of the relationship between the constitution and nuclear weapons. One of the key points in the government's interpretation of Japan's right of “individual self-defense” under Article 9 of the constitution (the so-called war renunciation clause) has been that “the use of armed strength” must be “confined to the minimum necessary level.” Following the line of reasoning originally laid out by Kishi in 1957, the Cabinet Legislative Bureau stated that the test of whether or not possession (hoyū) of nuclear weapons is constitutional depends on whether or not such weapons are within the confines of what would be minimally necessary for self-defense.8

This constitutional doctrine has been repeatedly reaffirmed by Japanese government officials. In 2002, both Abe Shinzō and Fukuda Yasuo, who were then serving as deputy chief cabinet secretary and chief cabinet secretary, respectively, stirred controversy by noting that the possession of nuclear weapons would be constitutional within the limits of what is minimally necessary for self-defense. Fukuda went further by stating that Japanese citizens might start to favor the acquisition of nuclear weapons if the international security environment should change dramatically.9 More recently, the Japanese government reconfirmed the constitutional doctrine regarding nuclear weapons in response to written questions submitted in Japan's National Diet by Representative Suzuki Muneo in November 2006.10 This doctrine suggests that if the threat environment changed so that nuclear weapons became minimally necessary for self-defense purposes, such weapons would be permissible. Moreover, the constitutional constraint appears to apply to Japan's own possession of nuclear weapons, but does not apply to introducing such weapons into Japanese territory by another state like the United States.

Japan's decision to forgo nuclear weapons has been linked to its reliance on U.S. extended deterrence. When Prime Minister Satō Eisaku first articulated the three non-nuclear principles and opposition parties insisted that the principles be affirmed with a Diet resolution, Satō proposed that Japan's nuclear policy be framed in terms of four pillars: the three non-nuclear principles, nuclear disarmament, reliance on U.S. nuclear deterrence, and the peaceful use of nuclear energy. In fact, in December 1964, Satō suggested to Edwin O. Reischauer, then U.S. ambassador to Japan, that it is common sense that Japan might possess nuclear weapons. The implication of this message was transmitted loud and clear to Washington. A month later, President Lyndon Johnson and Prime Minister Satō issued a joint communiqué in which Johnson “reaffirmed the United States’ determination to abide by its commitment under the [Security] Treaty to defend Japan against any armed attack from the outside.” The Japanese interpreted this statement as obligating the United States “to defend Japan from nuclear attacks with both conventional and nuclear forces.”11 The critical role of America's so-called nuclear umbrella over Japan has continued to be reaffirmed for Japan's defense policy. For example, the latest National Defense Program Guidelines approved in 2004 stated that “to cope with the threat of nuclear weapons, Japan continues to rely on the nuclear deterrent provided by the United States, while at the same time play an active role in taking realistic step-by-step measures for nuclear disarmament and nonproliferation.”12

Foundations of Japan's Non-Nuclear Weapons Policy

Analysts of nuclear proliferation have identified a number of factors that drive states to acquire nuclear weapons or prevent them from doing so. They include security calculations, national identity and symbolism, parochial bureaucratic and political interests within states, the nature of a state's governing coalition (whether it is liberalizing or nationalist), public attitudes and domestic political imperatives, technical obstacles and opportunities, U.S. foreign and security policy, and the relative robustness of global nonproliferation agreements and arrangements.13 In the Japanese case, three factors have been particularly salient in determining Japan's policy toward nuclear weapons: national identity as a peace and non-nuclear weapon state, commitment to the global nonproliferation regime and related agreements, and realist security calculations including the alliance with the United States. Although there has been some tension between these three factors, they have on the whole reinforced each other to sustain a durable foundation for Japan's nuclear restraint.

National Identity as a Non-Nuclear Weapon State

Japan's post–World War II national identity has focused around the notion of a “peace state” (heiwa kokka). This formulation emerged because of the devastating national consequences of pre-1945 militarism and was enshrined in Article 9 of the Japanese constitution that renounced the right of belligerency. A popular culture of antimilitarism provided a robust social underpinning for this national identity.14 But Japan's postwar pacifism was also pragmatic. The country retained the right to defend itself and maintain the minimally necessary self-defense forces for that purpose. Central to Japan's defense policy is the concept of an “exclusively defense-oriented policy” (senshu bō'ei) or “passive defense strategy” (judōteki na bō'ei senryaku).15 Moreover, Japan has stressed that it has no intention of becoming a military power “that might pose a threat to the security of other countries.”16

Although the government interpreted the constitution as prohibiting the exercise of the right of “collective self-defense” (as opposed to the permissible “individual self-defense”), Japan was willing to sign a bilateral security pact with the United States. According to Soeya Yoshihide, Japan has had a dual identity with respect to security: “a potential great power” that can shape the international security structure and “a self-restraining state” that manifests its domestic culture of pacifism and antimilitarism. The alliance with the United States enabled Japan to reconcile these two identities in its own version of realism.17

Despite this pragmatic pacifism, forgoing nuclear weapons has been central to Japan's identity as a “peace state.” Since their country has been the only one attacked by atomic weapons, many Japanese believe that they have a moral imperative to warn the world of the horror that nuclear weapons can bring. This view is more than just an impulsive “nuclear allergy.” Antinuclear sentiments are reinforced and reproduced through antinuclear educational programs, popular culture, and public ceremonies that insure that the experiences of Hiroshima and Nagasaki are not forgotten.18 No wonder that poll after poll have shown little public support for nuclearization. In fact, popular support for nuclear weapons actually declined after the end of the Cold War, even as Japan's security environment became more uncertain.19 A survey conducted by the Asahi Shimbun in summer 2005 revealed that only 6 percent favored nuclearization, while 86 percent were opposed.20 Public antinuclear sentiments have remained solid even after the October 2006 North Korean nuclear test. For example, according to a national survey conducted by the Yomiuri Shimbun on November 11–12, 2006, 80 percent of the respondents favored maintaining the three non-nuclear principles, while only 18 percent supported revising these principles. The survey yielded this result despite the fact that 74 percent of the respondents were not optimistic that the North Korean nuclear problem would be resolved through the six-party talks.21

Japan has been recalibrating its “peace state” security policies to deal with new security challenges.22 But the “non-nuclear” element of national identity remains a powerful constraint as the country “normalizes” as a security actor. If becoming a nuclear weapon state is a necessary condition (if not a sufficient one) to achieve great power status, then Japan's postwar national identity points toward an international role as a “middle power” rather than as a great power.23 Using the analytical language of social psychology, Maria Rublee argues that a large portion of the Japanese populace as well as many politicians and foreign policy officials “have been persuaded specifically that nuclear weapons are morally wrong and this can never be considered as a legitimate political or military tool.” Moreover, the Japanese have “accepted transformed definitions of security, power, and prestige in today's international system,” and therefore, Japan's “national interest does not include military might.”24 Indicative of this collective psyche is the reason that many Japanese citizens give for why their country should become a permanent member of the UN Security Council: “the participation of a non-nuclear country would contribute to world peace.”25

Even within conservative circles, support for Japan's identity as a non-nuclear weapon state continues to be strong. This is evident in the way many conservatives have engaged the question of revising the constitution. After Japan was criticized internationally for its response to the 1990–1991 Persian Gulf crisis and war, the conservative Yomiuri Shimbun, Japan's largest circulating newspaper, launched an examination in 1992 of constitutional revision that involved a number of mainstream experts on security policy. This project produced in 1994 a proposal for constitutional revision that contained the following clause: “The Japanese people, aspiring for the elimination of inhumane indiscriminate weapons of mass destruction [WMD] from the world, will not of their own accord produce, possess, or use such weapons.”

Arguing that Japan's policy of forgoing nuclear weapons should be elevated to the constitutional level, Yomiuri reaffirmed in 2004 its support of this no-WMD clause even while advocating that the constitution include explicit wording for a military (guntai) for self-defense.26 The initial 2004 outline for constitutional revision sketched out by the LDP Constitutional Reform Committee included a proposal to have the three non-nuclear principles incorporated into the constitution. Although this idea was eventually dropped in the 2005 draft, the fact that it ever emerged suggests how committed many LDP parliamentarians are to a non-nuclear weapons policy.27 Hatoyama Yukio, secretary general of the Democratic Party (the largest opposition party), has proposed his own draft for a new constitution that recognizes Japanese collective security activities and a self-defense military (ji-ei gun). But at the same time, he explicitly incorporates the three non-nuclear principles in his constitution revision proposal.28 These proposals suggest that even as Japan dilutes somewhat its national identity as a “peace state,” there will be influential voices on behalf of preserving the nation's identity as a “non-nuclear weapon” state.

Commitment to Global Nuclear Nonproliferation and Disarmament

The fact that Japan signed in 1970 and ratified in 1976 the NPT provides an additional underpinning for its non-nuclear policy. Japan initially delayed ratification because of its interest in securing equality with the European Atomic Energy Community (EURATOM) countries for using nuclear energy for peaceful purposes and in buttressing America's security commitment to Japan. There was also some domestic debate about whether Japan should retain the option to go nuclear and whether Japan should press more vigorously for nuclear disarmament.29 But after ratification, Japan has evolved into an enthusiastic NPT supporter. According to Rublee, “Japan's faith in the NPT is not because policymakers believe that it will definitely keep other states from pursuing a nuclear option (although they hope it will), but rather because it furthers the norm that they believe in.”30

Since the 1990s, the Japanese government has allocated more resources to nonproliferation and disarmament policy and has enhanced the prominence of this issue in its public diplomacy. Recent Japanese initiatives in this field include hosting UN conferences on disarmament issues, introducing nuclear disarmament resolutions to the UN General Assembly, training officials from developing countries about arms control and nonproliferation, providing financial and technical aid for the completion of the CTBT, persuading like-minded countries to join the CTBT, supporting a nuclear-weapon-free zone in Central Asia, and assisting denuclearization efforts in the former Soviet Union.31 When France and China tested nuclear devices in the mid-1990s, Japan issued strong protests and even temporarily froze grant aid to China.32

During the 2000 NPT Review Conference, Japan played a constructive role by mediating between the nuclear weapon states and the seven states in the New Agenda Coalition (NAC) that were demanding faster progress on nuclear disarmament. There was some delay in Japan approving the NPT's indefinite extension, but this foot-dragging did not indicate that Tokyo wanted to keep open its nuclear option, as some foreign observers surmised. Rather, it wanted to maximize leverage on North Korea not to withdraw from the NPT and to press the nuclear weapon states, including the United States, to scale back their nuclear arsenals as mandated in Article 6 of the treaty.33

After the Indian and Pakistani nuclear tests in 1998, Japan froze new aid grants and loans to both countries and introduced a UN resolution to condemn the tests. Tokyo also proposed a nuclear nonproliferation forum to address the security concerns that might have motivated both India and Pakistan to conduct the tests as well as to pressure nuclear weapon states to move more forthrightly toward nuclear disarmament. This initiative, however, raised enough concerns among the five permanent members of the UN Security Council (including the United States) that Japan ended up being excluded from a Security Council meeting in Geneva to discuss the South Asian nuclear tests. Nevertheless, the Japan Foreign Ministry inaugurated a Track-II Tokyo Forum involving specialists from 16 countries to examine the issue. This forum published in July 1999 a report that advocated a comprehensive approach that would link the objective of nuclear nonproliferation with the problems of biological and chemical weapons and of ballistic missiles.34

Following the October 2006 North Korean nuclear test, Japan acted swiftly to impose sanctions. It blocked all imports from North Korea, prohibited North Korean vessels from entering Japanese ports, and barred North Korean citizens from entering Japan (except those already residing in Japan). Japan also extended to more groups and individuals the ban on financial transfers and remittances from Japan to North Korea that had been imposed after the July 2006 North Korean missile tests.35

If Japan wanted to move toward the development and possession of nuclear weapons, the formal procedure for withdrawing from the NPT is not difficult. But given the rhetorical and policy investment that Japan has made in support of the NPT and Japan's international image as a non-nuclear weapon state, the reputational consequences would be severe. For Japan, it would not just be a matter of dropping out of the NPT, but rather reversing and repudiating a diplomatic track record that it has laid out over three decades.

Such a move would also violate bilateral agreements that enable Japan to continue its nuclear energy programs. According to Kaneko Kumao, a retired career diplomat who once directed the Foreign Ministry's Nuclear Energy Policy Division, Japan has bilateral nuclear agreements with the United States, the United Kingdom, France, Canada, and Australia that stipulate that “everything Japan has imported from these countries, including reactors, related equipment, nuclear fuel (natural and enriched uranium), and nuclear technology, must be used only for the non-military purposes specified in the agreement.” If Japan were to renege on these agreements, then it would face stringent sanctions “including the immediate return of all imported materials and equipment to the original exporting country.” Kaneko writes: “Should that ever happen, nuclear power plants in Japan will come to a grinding halt, crippling economic and industrial activities. It is simply unthinkable that the nation would be willing to make such a heavy sacrifice—unless it were really prepared to start a war. In this sense, the bilateral nuclear energy agreements provide a rather effective deterrent, certainly more effective than the NPT.”36

More recently, former Japanese Defense Minister Ishiba Shigeru made a similar point about the negative ramifications on its nuclear energy programs should Japan decide to develop nuclear weapons.37 Japan's lack of indigenous natural uranium sources further constrains a nuclear weapons breakout. For example, Australia, which supplies about 33 percent of Japan's uranium imports, will sell uranium only to NPT member states.38 To reduce its dependence on imported uranium, Japan has been especially attracted to the development of a complete nuclear energy cycle including breeder reactors.39 Nevertheless, it remains keenly interested in maintaining long-term, reliable sources of natural uranium.

Realist Security Calculations

In addition to its national identity as a non-nuclear weapon state and its active commitment to global nonproliferation, Japan's policy of forgoing nuclear weapons has also been based upon sober realist calculations. According to some versions of realist theory (e.g. Kenneth Waltz's structural realism), Japan ought to go nuclear simply because the anarchic nature of the international system would compel it to opt for “self-help” ways to ensure its security.40 This of course has not yet happened. But other variants of realist analysis suggest that Japan could maintain a non-nuclear stance and still be consistent with realism. For example, following the logic of “defensive realism,” a state may try to avoid a vexing security dilemma with other states by relying on the extended nuclear deterrence of a powerful ally rather than developing its own nuclear deterrent.41 Even under the logic of “offensive realism,” some states may choose not to become a “great power” by maximizing power to achieve security. According to John J. Mearsheimer, although contemporary Japan has the potential to become a great power, it is in reality a “semi-sovereign state” that relies on the U.S. nuclear deterrent for its security. Japan could continue to “buck-pass” to the United States as long as the latter remains militarily engaged in the Asia-Pacific region and is committed to Japan's defense.42 But to avoid abandonment by its protector, Japan has a strong incentive to tighten its alliance with the United States.43

Japan's foreign and security policy community has indeed examined the option to acquire nuclear weapons in terms of the above realist calculations and has concluded that it was not in Japan's security interest to acquire such weapons. About the time it enunciated the three non-nuclear principles in 1967, the Japanese government commissioned an academic group to “explore the costs and benefits of Japan's nuclearization in a comprehensive way.” The results of the study were articulated in two secret reports—one in 1968 and the other in 1970. In addressing the possibility that China would acquire the capability to strike the United States with intercontinental ballistic missiles by the 1970s, the study group concluded that U.S. extended deterrence over Japan and South Korea would constrain China from militarily intervening in East Asia. Moreover, it argued that even if Japan developed a small nuclear arsenal, it would remain highly vulnerable if attacked by nuclear weapons. Rather than enhancing Japanese security, nuclearization could alarm even the United States and lead to Japan's diplomatic isolation. These reports concluded that Japan's status as a non-nuclear weapon state was actually a positive factor for its national security and recommended that Japan promote its security “through a multi-dimensional approach including political and economic efforts, and not through a traditional militaristic, power-based approach.”44

During the 1990s, the Japan Defense Agency organized several internal study groups to examine the nuclear option in the context of the post–Cold War era and of concerns about North Korea's clandestine nuclear weapons program. A 1995 report entitled “A Report on the Problems of the Proliferation of Weapons of Mass Destruction” that was drafted by one of these study groups for internal use concluded that the acquisition of nuclear weapons would be undesirable. The report considered two scenarios. Under one scenario, the U.S.-Japan alliance would remain strong and the NPT regime would be maintained. The study concluded that if Japan opted for nuclear weapons under these circumstances, the U.S. nuclear umbrella would weaken, and Japanese nuclearization would promote nuclear proliferation. The second scenario involved abrogation of the U.S.-Japan alliance and collapse of the NPT regime. Even under this situation, the report argued that the nuclear option would run counter to Japanese national interests because it would foster an environment that would undermine Japan's prosperity as a trading nation. The better response in this disturbing scenario would be to reconsider fundamentally its conventional defense posture rather than to go nuclear. The overall recommendation of the 1995 study was, therefore, to develop ways to make sure that America's defense commitment to Japan remained solid.45

Although these cost/benefit calculations yielded the conclusion that it would be better for Japanese security to stick to nuclear forbearance, the Japanese government also felt that it made sense to retain at least a latent capability to exercise the nuclear option. For example, a 1969 Foreign Ministry internal document entitled “An Outline of Japanese Foreign Policy” (“Waga Kuni no Gaikō Seisaku Taikō”) stated that in adopting a policy of not possessing nuclear weapons, care should be given “to maintain always and not to restrict the economic and technological potential to produce nuclear weapons.”46 Japan does indeed have an advanced nuclear energy program and a large stockpile of reactor-grade (not weapons-grade) plutonium that could be the basis for developing nuclear weapons. Although domestic law prohibits nuclear engineers from studying nuclear weapons technology, they probably have the necessary expertise to become proficient in that technology if the legal prohibition were removed and the state directed them to do so. Perhaps a more formidable barrier might be the development of effective delivery vehicles (e.g. ballistic missiles and submarines) and a good command and control system. There is little indication that current nuclear energy and space-related activities might be related to a hidden nuclear deterrent program.47 But if Japan did decide to exercise the nuclear option, it should be able to do so over a reasonable period of time.

Some of Japan's realist calculations rub up against its national identity as a non-nuclear weapon state and its commitment to the NPT and nuclear disarmament. But policymakers have tried to reconcile the seeming contradictions. For example, how can Japan insist on promoting nuclear disarmament and getting the CTBT to go into force when it relies on U.S. extended nuclear deterrence? Tokyo has certainly been irritated by Washington's unwillingness to ratify the CTBT and its slowness to reduce its nuclear arsenal.48 But Japanese policymakers claim that this attitude does not necessarily contradict the critical role of the U.S. nuclear umbrella. They distinguish between setting complete nuclear disarmament as a long-term goal and taking the “concrete and practical steps leading to that goal.” Accordingly, while the international situation that might make “total elimination of nuclear weapons” feasible may seem unclear for the foreseeable future, steps can still be taken toward that goal now without undermining U.S. extended deterrence. Regarding the CTBT, Japanese policymakers stress that not having the treaty enter into force allows nuclear explosive tests to resume sooner or later. They question whether U.S. adherence to the CTBT would actually erode confidence in the technical reliability of U.S. nuclear weapons and therefore the deterrent effect they provide. They also point out that the CTBT has safeguards for addressing the reliability issue.49

Another apparent contradiction between Japan's strong support of the NPT regime and its realist calculations concerns its nuclear energy policy. After the oil shocks of the 1970s, Japanese policymakers saw nuclear energy as crucial for national energy security, and they have been attracted to a plutonium-based complete nuclear fuel cycle because of its potential as a never-ending source of energy. It has therefore embraced the development of fast-breeder reactors, nuclear fuel reprocessing, and the use of MOX (uranium/plutonium mixed oxide) fuel in nuclear reactors. But this policy challenges the NPT regime by provoking international suspicions about Japan's growing plutonium stockpile, by tempting other countries to adopt similar policies, and by raising formidable safety and transport security issues.50 According to one recent estimate, Japan now has about 40 tons of plutonium that could be enough to make approximately 5,000 nuclear bombs.51 Because the plutonium is reactor-grade rather than weapons-grade, this does pose complex design hurdles for weapons development, but they are unlikely to be technically insurmountable.52

To reassure the world about proliferation concerns, Japan has subjected itself to rigorous international inspections and monitoring. Because Japan's nuclear energy program is the largest of any non-nuclear weapon state, about 20–30 percent of the International Atomic Energy Agency's (IAEA) inspections activity is focused on Japan.53 According to one report, monitoring of the Japanese reprocessing plant at Rokkasho has consumed up to 20 percent of the IAEA's annual nuclear safeguards budget.54 To bolster the nonproliferation regime, IAEA Director General Mohamed ElBaradei proposed in 2005 a five-year moratorium on building new uranium enrichment and reprocessing facilities and international control of such reprocessing facilities. The Japanese government has reacted coolly, arguing that Rokkasho is an existing facility, although it will not go into operation for commercial reprocessing of spent fuel until sometime this year.55 Reprocessing may not be cost effective, but Japan feels that domestic reprocessing would lessen the security risks of transporting spent fuel to overseas reprocessing centers. Reprocessing would also help reduce the amount of radioactive waste from nuclear power plants at a time when Japan's storage facilities for spent fuel are rapidly approaching full capacity.56

Renewed Debate about the Nuclear Question

During the early 1980s, some Japanese commentators openly argued that Japan should acquire nuclear weapons because U.S.-Soviet strategic nuclear parity and the Soviet deployment of SS-20 intermediate-range ballistic missiles (IRBMs) weakened U.S. extended deterrence for Japan. They advocated an independent strategic posture similar to Gaullist France. But this viewpoint got little traction in the public debate, as Washington and Moscow agreed to eliminate IRBMs, U.S.-Soviet relations improved under Ronald Reagan and Mikhail Gorbachev, and the Cold War came to an end.57

After 2002, serious intellectual debate about the nuclear question reemerged in Japan, but this time with much greater energy than in the early 1980s. This new round of debate was triggered by two key developments: (1) the failure of Prime Minister Koizumi Junichirō's diplomatic initiative toward North Korea in September 2002 to resolve the abduction issue, and (2) the unraveling of the 1994 Agreed Framework between the United States and North Korea because of suspicions that Pyongyang violated the agreement with a clandestine uranium enrichment program.58 The debate has intensified after North Korea's missile tests in July 2006 and its nuclear test in October 2006. Also fueling this Japanese discussion of the nuclear question have been the potential threat posed by China's military modernization and the erosion of the NPT regime in the wake of the Indian and Pakistani nuclear tests in 1998.59 The contending views in this new debate cluster around three general policy alternatives: (1) moving toward a nuclear weapons option, (2) promoting a more robust conventional defense posture and a stronger alliance with the United States, and (3) pursuing a more assertive non-nuclear diplomacy.

Embracing the Nuclear Option?

Japanese commentators who favor moving toward the acquisition of nuclear weapons stress the following three points.60 First, the end of the Cold War has weakened U.S. extended deterrence. During the days of bipolar U.S.-Soviet confrontation, the United States had a compelling global strategic rationale and ideological motivation to defend Japan against Soviet nuclear threats, even at the risk of retaliation against the American homeland. But according to Nakanishi Terumasa of Kyoto University, one of the most vigorous proponents of Japan's nuclearization, “Now that there is no longer any threat of Japan being drawn into the Communist camp, America has scant grounds to endanger itself in order to defend our country.”61 He goes on to say that this does not mean that the U.S. nuclear umbrella has become useless vis à vis nuclear threats from China and North Korea, but there is now enough uncertainty about American will to defend Japan that Japan should eventually acquire its own nuclear arms.

Second, Japanese advocates of the nuclear option note that the trend toward nuclear proliferation is probably impossible to stop completely. Ironically soon after the NPT was extended indefinitely in 1995, India and Pakistan conducted their nuclear tests. Rather than seeking to roll back India's nuclear weapons program, the United States eventually opted to recognize India as a nuclear power and sign a bilateral nuclear agreement. With the North Korean nuclear tests and the danger of Iran moving forward on nuclear weapons development, Japan should assume that the nuclear threat would continue to spread globally.

Finally, according to nuclearization advocates, because U.S. hegemony has now peaked, the United States will inevitably reduce its involvement in Asia over the longer term. At the same time, China will seek to establish hegemony in East Asia. One sign of possible U.S. disengagement from the region would be if the United States withdrew its forward deployed forces (especially on Japan) back to Guam and Hawaii. Also ominous for Japan would be Chinese development of a blue-water navy and the establishment of a regular naval presence near Okinawa and the Senkaku Islands in the East China Sea. To counter this unfavorable trend in the conventional military balance, Japan would need its own nuclear weapons.

Some Japanese advocate the acquisition of nuclear weapons so that Japan can pursue a foreign policy that is strategically independent of the United States.62 But other Japanese proponents of nuclearization argue that the United States may be warming up to the idea of a nuclear Japan. As evidence, they point to Vice President Richard Cheney's March 2003 television statement that North Korea's nuclear program might force other East Asian countries like Japan “to consider whether or not they want to readdress the nuclear question.”63 They also note that some American conservative commentators like Charles Krauthammer have started to support Japan moving to acquire its own nuclear deterrent in order to pressure China to squeeze North Korea. Given this emerging trend in American opinion, Japan would not necessarily be isolated from the United States if it did choose to go nuclear. The important thing would be to pursue this option in cooperation with the United States.64

The pro-nuclear weapons commentators acknowledge that it would probably take at least a decade for Japan to develop an effective nuclear deterrent. And even while stressing how the acquisition of nuclear weapons would enhance Japan's security, many of them refrain from advocating immediate nuclearization and instead emphasize the urgent need to break the public taboo against seriously considering the nuclear option.65 So in the meantime Japan should promptly take non-nuclear steps to counter the immediate threat from North Korean nuclear programs. These might include the acquisition of more advanced missile defense systems and Tomahawk cruise missiles for preemptive and retaliatory strikes. Soon after the North Korean nuclear test in October 2006, nuclear advocates like Nakanishi stressed the importance of Japan seriously considering the nuclear option so as to pressure both the United States and China to deal more forcefully with the nuclear threat that North Korea now poses against Japan. They also insist that Japan's nuclearization should be pursued as a complement to U.S. nuclear deterrence.66

Robust Conventional Defense and a Stronger Alliance with United States

Like the proponents of Japan's nuclearization, those who support a more robust conventional defense policy are concerned about a potential strategic decoupling between Japan and the United States, but they advocate other means to rectify the problem rather than Japan acquiring an independent nuclear deterrent.67

Some in this school of thought have highlighted a potential divergence between Tokyo and Washington about how to deal with a nuclear North Korea. For example, Nishihara Masashi, former president of Japan's National Defense Academy, expressed concerns that the United States might support a “non-aggression” pact with North Korea as part of a bargain to get Pyongyang to denuclearize. He feared that such an agreement might eventually lead to a U.S. military withdrawal from South Korea and even weaken America's commitment to defend Japan against a North Korean threat.68 After the North Korean nuclear test, Tanaka Akihiko of Tokyo University pointed out the different priorities between Japan and the United States. Whereas Japan's security is directly threatened by the possibility of North Korean nuclear missiles, the United States is more concerned about the proliferation of North Korean nuclear technology to other states and suspected terrorist organizations.69

Analysts in this opinion cluster are also concerned about the challenges that China can pose on Japanese security. Although the conventional military balance may be favorable to Japan at present, China could eventually overtake Japan, and even catch up to the combined air and naval capabilites of the United States and Japan in areas near the Japanese archipelago. China currently does not have a nuclear counterforce capability to threaten the U.S. ability to retaliate against China and does not possess a credible and survivable second-strike capability against the United States. Under the present situation, U.S. extended deterrence against China would be credible at the nuclear level because the United States would control the escalatory ladder. Extended deterrence, however, could become problematic if the conventional military balance near Japan tips in China's favor, if China concentrated on beefing up theater nuclear forces that threaten Japan, or if China developed more robust strategic nuclear forces that could threaten American urban centers.70

Commentators in this school of thought, however, disagree with the claim of nuclear weapons advocates that the United States would consider and even support Japan's nuclearization. They also believe that exercising the nuclear option could ultimately jeopardize Japan's security interests by not only making Japan's relations with the United States problematic, but also provoking a nuclear arms race in the region. If such an arms race ensued, Japan would be at a disadvantage because its territory is so geographically narrow and the country is so densely populated and urbanized.71

But even while arguing against the nuclear option, these analysts believe that Japan needs to take non-nuclear countermeasures to bolster national security, and there is a wide range of opinion regarding what these countermeasures ought to be. Many advocate further strengthening of U.S.-Japan defense cooperation and accelerating the acquisition of a multi-layered missile defense system.72 Because the effectiveness of U.S. extended deterrence depends upon how potential adversaries view the robustness of the U.S.-Japan alliance, they support reinterpreting or revising the constitution so that Japan can exercise the right of collective self-defense in order to be a more pro-active ally of the United States. Regarding missile defense, these commentators recommend removing any potential constitutional obstacles to Japan using its future missile defense system to intercept missiles that might be headed toward the United States. Some argue that Japan should explore the possibility of greater integration with U.S. nuclear strategy along the lines of NATO's “nuclear sharing” concept.73 Others advocate relaxing the third of the three non-nuclear principles so that the transit of U.S. nuclear-armed warships would be permitted in order to buttress extended deterrence.

In addition to strengthening the U.S.-Japan alliance, proponents of non-nuclear countermeasures stress the need to ensure that the conventional military balance between China on the one hand and Japan and the United States on the other in terms of naval and air capabilities in areas near Japan does not tip in China's favor. Therefore, if China's military modernization and buildup continues, Japan should consider enhancing its own naval and air capabilities. Another non-nuclear countermeasure that is becoming increasingly discussed is the acquisition of conventional retaliatory capabilities such as cruise missiles. One analyst has even declared that if the ultimate objective is to make the U.S.-Japan alliance comparable to the U.S.-British alliance in terms of tightness and trust, then just as the United States has provided Tomahawk cruise missiles to the United Kingdom, it should provide the same to Japan.74

But even while supporting Japan's nuclear restraint, analysts in this opinion cluster feel that it would be prudent to study and debate the nuclear option. It would not be in Japan's national interest for the international community to take for granted Japan's non-nuclear weapons policy. By demonstrating its willingness to “research” various options including nuclearization, Japan would gain leverage over the United States to make sure that Washington does not weaken its defense commitment to Japan and over China to use its influence with North Korea to insist on denuclearization.

Assertive Non-Nuclear Diplomacy

The third cluster of opinion supports a Japan that not only sticks to its traditional non-nuclear policy, but also promotes this policy more assertively in the international arena.75 By being the only country to suffer from atomic attacks, Japan has the moral authority and duty to convince the rest of the world that nuclear weapons do not lead to greater security. Given that Japan has staked its global reputation on behalf of nuclear nonproliferation and disarmament, a shift toward a pro-nuclear policy would more than undermine the U.S.-Japan alliance. It could also provoke stern international rebuke and lead to isolation similar to when Japan departed from the League of Nations in the 1930s.76

While condemning the North Korean nuclear tests, these commentators are also critical of U.S. foreign policy. They point out that the preventive war and preemptive strike doctrines and the hostile rhetoric of the United States under the Bush administration have contributed to motivating some states, including North Korea, to go nuclear. They also criticize America's refusal to ratify the CTBT and to be more energetic in reducing its own nuclear arsenal. And they are unhappy with how Washington has accepted India as a nuclear weapon state.

To deal with North Korea's nuclear weapons program, proponents of a more assertive non-nuclear diplomacy argue that the international community should take steps to address Pyongyang's security concerns by upgrading the Korean Peninsula armistice agreement to a peace agreement and by normalizing relations with North Korea. Japan should work with other countries to use positive incentives, including economic assistance, to induce North Korea to freeze its nuclear weapons development program and to accept IAEA inspectors.77 According to Sakamoto Yoshikazu of Tokyo University, Japan would be irrational to counter North Korean nuclear weapons with nuclear weapons of its own because such a response would weaken even further the NPT regime.

Many of the assertive non-nuclear advocates also stress the need for Japan to move away from relying on U.S. extended nuclear deterrence for its own security. But rather than pushing for conventional armaments for Japan's defense, they believe the more effective approach would be to promote regional confidence-building measures and a cooperative security order—–even an “East Asian community.” They embrace many of the ideas and proposals contained in the June 2006 report of the independent Weapons of Mass Destruction Commission, entitled Weapons of Terror: Freeing the World of Nuclear, Biological, and Chemical Weapons.78 They support the notion that nuclear weapons should be made illegal and that security should be achieved without dependence on nuclear weapons.79 With this objective in mind, some in this opinion cluster persist in calling for a “nuclear-weapon-free zone” in Northeast Asia.80

Another dimension of a more assertive non-nuclear diplomacy concerns Japan's nuclear energy programs. Some in this opinion cluster assert that Japan needs to shift away from its current policy of using recycled nuclear fuel. They emphasize how Japan's plutonium use can undermine the NPT regime. Others advocate the establishment of a nuclear energy institution in the Asia-Pacific comparable to EURATOM in Europe. The purpose of such a regional multilateral framework would be to enhance the transparency and safety of nuclear energy programs and to reduce the risk of nuclear weapons proliferation.81

Japanese Policy Responses

How the above strategic debate will actually affect Japan's policy toward nuclear weapons will depend on potential changes in the three foundations of Japan's nuclear restraint discussed earlier in this article. The three factors of national identity as a peace and non-nuclear weapon state, commitment to global nuclear nonproliferation and disarmament, and realist security calculations have worked together to sustain the current policy line. At this point, it is impossible to know whether any of these three factors have been either necessary or sufficient to explain Japan's non-nuclear weapons policy. For example, it is impossible to determine whether U.S. extended deterrence was necessary or sufficient because America's repeated assurances to Japan about its security commitment precluded a real test of the power of Japan's national identity as a non-nuclear weapon state as an explanatory factor. Similarly, because the NPT regime was strong and largely unchallenged for three decades, it is difficult to know how much Japan's energetic commitment to that regime depended upon the regime's continued effectiveness.

There is now a potential for at least partial change in each of the three factors. First, Japan has been incrementally softening its national identity as a peace state by enhancing defense cooperation with the United States, by participating in overseas peacekeeping operations, by deploying ground forces to Iraq for postwar reconstruction, and by upgrading the defense agency into a full-fledged ministry. Second, although Japan remains committed to global nuclear nonproliferation and disarmament, this international regime has eroded considerably in recent years, raising questions about the efficacy of Japan's commitment to this regime. Finally, Japan's immediate security environment has deteriorated with North Korea's nuclear and missile tests and China's military modernization programs.

These changes so far do not amount to a wholesale degradation of the three foundations of Japan's nuclear restraint. Japan continues to identify itself as a non-nuclear weapon state; the NPT regime has weakened but has not been abandoned by the major powers; and the positive state of U.S.-Japan political and security relations sustains the credibility of U.S. extended deterrence. But if North Korea advances from one nuclear test to full-scale nuclear weaponization, and if China's military buildup continues, the tensions among the three underpinnings of Japan's non-nuclear policy might become increasingly salient. For example, rather than Japan's non-nuclear national identity and its realist calculations reinforcing each other on behalf of nuclear restraint as in the past, there is likely to be a tug-of-war between the former and latter factors.

Because of this tug-of-war between Japan's non-nuclear identity and realist calculations, Japanese policies are likely to gravitate around the recommendations of those who advocate non-nuclear realist responses to the more worrisome regional security environment. This means that Japan is likely to strengthen further its security relationship with the United States, to accelerate its missile defense programs, and to loosen the current constitutional prohibition on exercising the right of collective self-defense. There may also be a relaxation of the third non-nuclear principle to allow the transit of nuclear-armed American ships if such a change is requested by the United States.

Japan already appears to be moving in this direction. Although supportive of the six-party talks with North Korea, the Japanese policy community and public are not optimistic that the process will compel North Korea to give up completely its nuclear weapons program.82 Given this situation, Japanese policymakers have proposed reexamining constitutional doctrine to see whether it would be permissible to shoot down missiles that might be headed toward U.S. naval vessels operating near Japan or even toward U.S. territory.83 In late November 2006, Defense Minister Kyūma Fumio stated that it might be unavoidable for Japan to allow U.S. ships carrying nuclear weapons to pass through Japanese waters. The passage of such U.S. ships through Japanese territorial waters and harbors is now a moot issue following the 1991–1992 withdrawal by the United States of all operationally deployed sea-based nuclear weapons, except for those aboard Trident submarines (which do not make overseas port calls).84 Nevertheless, Kyūma was signaling possible Japanese willingness to relax the third non-nuclear principle of not permitting the introduction of nuclear weapons in Japan in order to bolster U.S. extended deterrence.85 There have also been press reports that Japan's Ministry of Defense is likely to ask the United States about how the U.S. nuclear umbrella would actually function during a military contingency, including that involving North Korea.86

A more controversial step would be for Japan to move away from its exclusively defensive-oriented posture to one that includes conventional retaliatory capabilities, such as cruise missiles or fighter aircraft.87 In 2004, then-Defense Minister Ishiba Shigeru did ask the National Institute for Defense Studies (NIDS), a think tank affiliated with the Japan Defense Agency, to study Japanese options for attacking the mobile launch platforms of North Korean Nodong medium-range missiles. The NIDS study concluded that the F-22 Raptor stealth fighter would be more effective than cruise missiles because of the cruise missiles’ limited ability to change trajectories after launch.88 But when asked by the Yomiuri Shimbun on October 14–15, 2006 (soon after the North Korean nuclear test) whether or not Japan should have the capability to attack missile bases of Japanese adversaries, 53 percent of the public surveyed opposed such a capability, compared to 41 percent who favored it.89 In addition to the absence of strong public support for this option, it is far from clear whether the acquisition of such retaliatory capabilities would strengthen deterrence against a serious nuclear threat more than strengthening the alliance with the United States. Furthermore, a shift from an exclusively defensive-oriented policy to a military posture that includes counter-offensive capabilities could exacerbate security dilemmas with neighboring countries like South Korea and China that Japan has traditionally tried to avoid.

Japan, however, is likely to debate much more publicly and seriously the nuclear question. Public opinion surveys indeed suggest that it is no longer taboo to discuss whether or not Japan should acquire nuclear weapons. For example, according to a survey conducted by the Mainichi Shimbun in November 25–26, 2006, 61 percent favored debating the nuclear issue, even while opposing the possession of nuclear weapons. In fact, support for this view cuts across political party lines. Among those backing the LDP and the Kōmei Party (Kōmeitō) in the governing coalition, 62 percent of the former group and 57 percent of the latter group favored debating the nuclear issue while opposing the acquisition of nuclear weapons. But among supporters of the opposition Democratic Party, even a larger percentage held this view: 74 percent.90 In this context, policymakers will find it easier to promote discussions about the nuclear option at the non-governmental level in order to strengthen Japan's international leverage—whether to get other countries to press harder and more effectively for North Korean denuclearization or to prevent the United States from weakening its security commitment to Japan.

Nevertheless, Japanese research institutes addressing foreign policy issues are still likely to tread lightly on the nuclear question. One indication of this is the example of the Institute for International Policy Studies (IIPS), the mainstream think tank founded by former Prime Minister Nakasone Yasuhiro. On September 5, 2006 (a month before the North Korean nuclear test), IIPS released its report entitled “A Vision of Japan in the 21^st Century” (“21 Seiki no Nihon no Kokka Zō ni tsuite). In the section on “Respond to new threats—formulate an independent defense strategy,” the IIPS report stated the following:

Japan should maintain its stance as a non-nuclear nation and work to strengthen the nonproliferation treaty regime. At the same time, in order to prepare for drastic changes in the international situation in the future, a thorough study of the nuclear issue should be conducted.

We must define our respective roles in strategic goals shared with the United States and further solidify our alliance while working to consolidate and rationalize military bases in Japan. To ensure that we can appropriately respond to any national security situation, we should boost our defense capabilities. As one component of this, if Japan faces an imminent security threat, the use of force against enemy bases as an act of self-defense should not be ruled out.91

At the press conference when IIPS report was released, Nakasone was quoted as saying: “There is a need to also study the issue of nuclear weapons. There are countries with nuclear weapons in Japan's vicinity. We are currently dependent on U.S. nuclear weapons [as a deterrent], but it is not necessarily known whether the U.S. attitude will continue.”92 Nakasone's statement created quite a stir internationally because it suggested that mainstream Japanese statesmen like Nakasone and mainstream research institutes like IIPS were now seriously contemplating the nuclear option.

After the North Korean nuclear test, however, Ōkawara Yoshio, president of IIPS and former Japanese ambassador to the United States, gently chided LDP leader Nakagawa and Foreign Minister Asō for calling for a nuclear debate and tried to reassure the Japanese public and the international community about the September 2006 IIPS report. Ōkawara wrote the following in an opinion article for the Japan Times in November 2006:

Officials of the government and ruling parties directly involved in policymaking must be discreet about their remarks on the nuclear issue so as not to create undue international suspicions about Japan's intentions. Careless juggling of the nuclear option, particularly while the international community, including Japan, is pressing North Korea to scrap its nuclear program, might be exploited by other countries to criticize Japan's policy stance.

True, the government may be able to legitimize possession of nuclear weapons by a legal interpretation of the Constitution, but it is hard to imagine Japan's national interests being served by publicly proposing such a theoretical possibility. …

For its peace and security at present, Japan must make additional efforts to strengthen the Japan-U.S. alliance and deploy ballistic missile defense systems without delay in close cooperation with the U.S. while maintaining its non-nuclear principle.93

Ōkawara went on to mention several leaders in both the ruling LDP and the opposition DPJ who have steadfastly supported Japan's non-nuclear policy. With this Ōkawara article, the IIPS backtracked from the September 2006 Nakasone statement and signaled that it would not take the lead in discussing the nuclear option.94

Domestic changes within Japan could certainly alter the terms of debate about the nuclear issue. If Japan were to revise its constitution to recognize unequivocally a “self-defense military” and to permit Japan to use force in some circumstances beyond defense of the homeland, then Japan's identity as a peace state would either be diluted or at least recalibrated to enlarge the permissible political space for discussing nuclearization. Or as Llewelyn Hughes has suggested, the increasing centralization of executive power and authority regarding foreign and security policy might mean that the emergence of a Japanese political leader who favors considering the nuclear option might wield considerable influence in shaping public opinion.95

But these factors in themselves are unlikely to push Japan over the “nuclear tipping point.” In the final analysis, it is likely to be a combination of external factors that will drive Japan to cross the nuclear threshold. The external factors that matter will be an even greater deterioration of the regional security environment combined with a significant shift in U.S. policy that includes tacit support for a nuclear Japan, U.S. abandonment of the nuclear nonproliferation regime, and a weakening of U.S. security commitments to Japan. Neither an increasing security threat nor a fundamental shift in U.S. policy alone will be sufficient to trigger a Japanese nuclear breakout. But the combination of these two factors could drive Japanese domestic shifts and weaken Japan's non-nuclear norm enough so that Japan would adopt a different strategic posture. Fortunately, we are not at that point yet.

Conclusion

Although U.S. policymakers have alluded to the danger of Japanese nuclearization to convince China and South Korea that these two countries should push harder to denuclearize North Korea, they have refrained from officially encouraging Japan to consider the nuclear option, despite opinion articles that argue for such a course, which appear every now and then in U.S. newspapers.96 Although the United States for balance-of-power reasons agreed in July 2005 to civilian nuclear energy cooperation with India outside the NPT regime, it is not “jettisoning the regime, but, rather selectively applying it in practice”—in the words of Ashley J. Tellis, one of the architects of this new U.S. policy.97 The U.S.-India nuclear energy agreement notwithstanding, Japan has so far refused to recognize India as a nuclear weapon state and has continued to want India to join the NPT as a non-nuclear weapon state.98 And while the U.S. review of force deployments in Japan as part of the Global Posture Review has produced plans to transfer some U.S. forces from Japan to Guam, neither Japan nor the United States sees this defense transformation as weakening U.S. will or capability to defend Japan. In fact, this transformation will encourage even further tightening of the U.S.-Japan alliance, thereby mitigating Japanese concerns about U.S. security abandonment.99 In fact, after the North Korean nuclear test, the U.S. Navy announced the deployment of a new guided-missile destroyer that would enhance missile defense capabilities near Japan. The Japan Defense Agency also announced that the United States and Japan are considering a joint bilateral facility in Nagasaki prefecture for maintaining interceptor missiles that would be used for ballistic missile defense.100

Regarding the regional security environment from Japan's perspective, although China's military modernization is worrisome for Japan in the long term, Japanese defense planners remain reassured that the combination of U.S. and Japanese naval and air capabilities continues to have a decisive conventional military edge over China in scenarios that might threaten Japanese security. And U.S. superiority over China regarding strategic nuclear forces sustains for Japan the credibility of U.S. extended nuclear deterrence. As shocking as North Korea's nuclear test has been, the agreement reached with North Korea at the six-party talks in mid-February 2007—albeit fragile and incomplete—suggests to the Japanese that it may still be possible to freeze, or at least slow down, North Korea's drive to develop an effective nuclear arsenal that can threaten Japan, even though it may be impossible to dismantle completely and irreversibly North Korea's nuclear program. And even if North Korea developed a threatening nuclear arsenal, Japan could still pursue, as Ken Jimbo has argued, a realist strategy of “multiple deterrence” that does not involve Japan's own nuclear deterrent: (1) nuclear and conventional extended deterrence by the United States, (2) denial deterrence through missile defense deployment, and (3) indigenous deterrence by Japan's own conventional defense capabilities.101

Korean reunification in the future could provoke both a fundamental rethinking of U.S. strategy in East Asia and a dramatically altered regional security environment. For example, a reunified and nuclear-armed Korea that is hostile to Japan and/or aligning with China would severely test, if not overwhelm, Japan's non-nuclear identity and strengthen realist calculations in favor of nuclear weapons—especially if the United States chooses or is compelled to retreat militarily. But such a strategic juncture remains only a remote hypothetical possibility for the time being. Despite North Korea's alarming nuclear ambition and brinksmanship, this factor does not alter the strategic landscape enough to drive Japan to go nuclear. It may have weakened the taboo in Japan to discuss publicly the nuclear weapons option, but it will not cause Japan to exercise that option.

Acknowledgements

The author would like to thank Llewelyn Hughes, Maria Rublee, and an anonymous reviewer for their helpful comments on an earlier version of this article.

Notes

1. U.S. Secretary of State Condoleezza Rice reaffirmed President George W. Bush's statement during her visit to Tokyo on October 19, 2006, 10 days after North Korea's underground nuclear test. Bruce Wallace, “U.S. Is Japan's Nuclear Shield, Rice Says,” Los Angeles Times, October 19, 2006, p. A7.

2. “‘Hi-Kaku’ Sairyō no Sentaku” (“Non-Nuclear” is the Best Choice), Asahi Shimbun (Tokyo), November 12, 2006, p. 3.

3. “Shushō, Kaku Rongi o Yōnin” (Prime Minister Approves Nuclear Debate), Asahi Shimbun (Tokyo), November 9, 2006, pp. 1, 4. Before international audiences, Prime Minister Abe has been more emphatic about his government's commitment to a non-nuclear weapons policy. For example, at a press conference after the Asia-Pacific Economic Cooperation Economic Leaders’ Meeting held in Hanoi in November 20, 2006, Abe made the following statement: “Japan is unique among all countries in the world in that it is the only country to have been attacked by nuclear weapons, and because of this tragic experience we believe we have the mission to take the lead in eliminating nuclear weapons from this world. Therefore, we have been making such efforts at the United Nations, amongst others. As such, we have abandoned the option of possessing nuclear weapons, and in the Japan-China Summit Meeting here in Hanoi as well, I stated that Japan shall steadfastly maintain its Three Non-Nuclear Principles. At the same time, I referred to the importance of the nuclear weapon states to engage in efforts to proceed with nuclear disarmament. In my administration and in the official organs of the Liberal Democratic Party, there will be no discussions on the possibility of possessing nuclear weapons. Let me make that very clear.” “Press Conference by Prime Minister Shinzo Abe Following the Asia-Pacific Economic Cooperation Economic Leaders’ Meeting,” November 20, 2006, <www.kantei.go.jp/foreign/abespeech/2006/11/20press_e.html>.

4. Regarding the concept of “nuclear tipping point,” see Kurt M. Campbell, Robert J. Einhorn, and Mitchell B. Reiss, eds., The Nuclear Tipping Point: Why States Reconsider Their Nuclear Choices (Washington, DC: Brookings Institution Press, 2004).

5. Article 2 of the Atomic Energy Basic Law, Japan Nuclear Cycle Development Institute Web Site, <www.jaea.go.jp/jnc/kaihatu/hukaku/english/atomiclaw.htm.>

6. Nobumasa Akiyama, “The Socio-Political Roots of Japan's Non-Nuclear Posture,” in Benjamin L. Self and Jeffrey W. Thompson, eds., Japan's Nuclear Option: Security, Politics, and Policy in the 21 ^st Century (Washington, DC: Henry L. Stimson Center, 2003), pp. 83–85; and Defense of Japan 2006 (Tokyo: Japan Defense Agency, 2006), pp. 95, 142.

7. Article 9 of the postwar constitution reads as follows: “Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes. In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.”

8. Bō'ei Handobukku 2006 (Defense Handbook 2006) (Tokyo: Asagumo Shimbunsha, 2006), pp. 577–579.

9. Katsuhisa Furukawa, “Nuclear Option, Arms Control, and Extended Deterrence: In Search of a New Framework for Japan's Nuclear Policy,” in Self and Thompson, eds., Japan's Nuclear Option, p. 105.

10. “Japan Can Legally Be Allowed to Possess Nuclear Arms, Government Says,” Kyodo News, November 14, 2006.

11. Akiyama, “The Socio-Political Roots,” pp. 81–82.

12. “National Defense Program Guideline for FY2005 and After,” Japanese Ministry of Defense Web Site, <www.jda.go.jp/e/index_.htm.>

13. Scott D. Sagan, “Why Do States Build Nuclear Weapons? Three Models in Search of a Bomb,” International Security 21 (Winter 1996/97), pp. 54–86; Etel Solingen, “The Political Economy of Nuclear Restraint,” International Security 19 (Fall 1994), pp. 126–169; Campbell, Einhorn, and Reiss, eds., The Nuclear Tipping Point; and Mitchell B. Reiss, “Prospects for Nuclear Proliferation in Asia,” in Ashley J. Tellis and Michael Wills, eds., Strategic Asia 2005–06: Military Modernization in an Era of Uncertainty (Seattle: National Bureau of Asian Research, 2005), pp. 333–360.

14. Thomas U. Berger, “From Sword to Chrysanthemum: Japan's Culture of Anti-Militarism,” International Security 17 (Spring 1993), pp. 119–150; and Peter J. Katzenstein, Cultural Norms and National Security: Police and Military in Postwar Japan (Ithaca, NY: Cornell University Press, 1996).

15. The Japan Defense Agency has defined the “exclusively defense-oriented policy” in the following manner: “The exclusively defense-oriented policy means that defensive force may not be employed unless and until an armed attack is mounted on Japan by another country in which case, it must be limited to the minimum level necessary to defend itself, and furthermore that the extent of the defense forces retained and the use of these forces should be kept to the minimum level necessary for self-defense. This exclusively defense-oriented policy thus refers to a passive defense strategy that is consistent with the spirit of the Constitution.” Defense of Japan 2006, p. 95.

16. The Japan Defense Agency has defined the “exclusively defense-oriented policy” in the following manner: “The exclusively defense-oriented policy means that defensive force may not be employed unless and until an armed attack is mounted on Japan by another country in which case, it must be limited to the minimum level necessary to defend itself, and furthermore that the extent of the defense forces retained and the use of these forces should be kept to the minimum level necessary for self-defense. This exclusively defense-oriented policy thus refers to a passive defense strategy that is consistent with the spirit of the Constitution.” Defense of Japan 2006, p. 95.

17. Yoshihide Soeya, “Japan: Normative Constraints Versus Structural Imperatives,” in Muthiah Alagappa, ed., Asian Security Practice: Material and Ideational Influences (Stanford, CA: Stanford University Press, 1998), pp. 228–233. Some prominent Japanese scholars, however, feel that Japan has not really reconciled internal contradictions of Japanese security policy, but rather has adopted “double standards.” See for example, Sakamoto Yoshikazu, “Kempō o Meguru Ni-jū Kijun o Koete: Ima, Nani o Genten to Suruka” (Overcoming the Double Standards Surrounding the Constitution: What Should Be Regarded as the Starting Point Now?), Sekai No. 743 (September 2005), pp. 45–57.

18. Maria Rost Rublee, “Persuasion, Social Conformity, and Identification: Constructivist Explanations for Non-Nuclear States in a Nuclear World,” Ph.D. dissertation, George Washington University, 2004, pp. 82–85; and Matake Kamiya, “Nuclear Japan: Oxymoron or Coming Soon?” Washington Quarterly 26 (Winter 2002/03), pp. 65–67.

19. Llewelyn P. Hughes, “Why Japan Will Not Go Nuclear (Yet): International and Domestic Constraints on the Nuclearization of Japan,” International Security 31 (Spring 2007), pp. 89–90.

20. Asahi Shimbun (Tokyo), August 6, 2005.

21. Yomiuri Shimbun (Tokyo), November 20, 2006.

22. Mike M. Mochizuki, “Paradigms Lost: Japan's Nationalist Drift,” American Interest 2 (September/October 2006), pp. 83–85.

23. Soeya Yoshihide, Nihon no “Midoru Pawā” Gaikō (Japan's “Middle Power” Diplomacy) (Tokyo: Chikuma Shobo, 2005).

24. Rublee, “Persuasion, Social Conformity, and Identification,” pp. 132–133.

25. Naikaku-Fu Daijin Kanbō Seifu Kōhō Shitsu, Gaikō ni Kansuru Yoron Chōsa (Public Opinion Survey Regarding Foreign Relations) October 2005, figure 35, <www8.cao.go.jp/survey/h17/h17-gaikou/images/z35.gif.>

26. Yomiuri Shimbunsha, ed., Kempō: 21 Seiki ni Mukete (Constitution: Pointing Toward the 21^st Century) (Tokyo: Yomiuri Shimbunsha, 1994), pp. 46–49; and Yomiuri Shimbunsha, ed., Kempō Kaisei: Yomiuri Shi-An 2004-Nen (Constitutional Revision: Yomiuri Draft 2004) (Tokyo: Chūō Kōron Sha, 2004), pp. 82–83, 335.

27. Hughes, “Why Japan Won't Go Nuclear (Yet).”

28. Hatoyama Yukio, Shin Kempō Shi-an: Songen aru Nihon o Tsukuru (New Constitution Draft: Creating a Japan that Has Dignity) (Tokyo: PHP Kenyūjō, 2005).

29. John E. Endicott, “The 1975–76 Debate Over Ratification of the NPT in Japan,” Asian Survey 17 (March 1977), pp. 275–292.

30. Rublee, “Persuasion, Social Conformity, and Identification,” p. 142.

31. Hughes, “Why Japan Won't Go Nuclear (Yet),” pp. 73–75; and Michael J. Green and Katsuhisa Furukawa, “New Ambitions, Old Obstacles: Japan and Its Search for an Arms Control Strategy,” Arms Control Today 30 (July/August 2000), pp. 19–20; and Yuri Kase, “Japan's Nonnuclear Weapons Policy in the Changing Security Environment: Issues, Challenges, and Strategies,” World Affairs 165 (Winter 2003), pp. 126–127.

32. Christopher W. Hughes, Japan's Security Agenda: Military, Economic and Environmental Dimensions (Boulder, CO: Lynne Rienner Publishers, 2004), pp. 198–199.

33. Green and Furukawa, “New Ambitions, Old Obstacles,” pp. 20–22.

34. Green and Furukawa, “New Ambitions, Old Obstacles,” p. 20; National Institute for Defense Studies Japan, East Asian Strategic Review 2000 (Tokyo: National Institute for Defense Studies, 2000), p. 89.

35. Hiroko Nakata, “Japan Makes It Official: More Punitive Steps Kick In,” Japan Times, October 14, 2006; and Reiji Yoshida and Masami Ito, “Japan Stands Firm with Sanctions on North Korea, Japan Times, November 2, 2006.

36. Kumao Kaneko, “Japan Needs No Umbrella,” Bulletin of the Atomic Scientists 52 (March/April 1996), p. 48.

37. Ishiba Shigeru, Kokubō (National Defense) (Tokyo: Shinchōsha, 2005), pp. 144–145.

38. Remarks by Japanese Amb. Hideaki Ueda to Australia at the Australian Institute of International Affairs, Perth, Australia, October 4, 2006, <www.japan.org.au/pdf/AIIA_WA_Address.pdf; and Hasane Masaki, “Japan Joins the Race for Uranium Amid Global Expansion of Nuclear Power,” Japan Focus, April 22, 2006, pp. 4–5, <www.japnfocus.org/products/topdf/1626.>

39. Richard J. Samuels, “Consuming for Production: Japanese National Security, Nuclear Fuel Procurement, and the Domestic Economy,” International Organization 43 (Autumn 1989), pp. 633–634.

40. Kenneth N. Waltz, The Spread of Nuclear Weapons: More May Be Better, Adelphi Paper No. 171 (London: International Institute for Strategic Studies, 1981).

41. For a discussion of defensive realism, see Jeffrey W. Taliaferro, “Security Seeking under Anarchy: Defensive Realism Revisited,” International Security 25 (Winter 2000/1), pp. 128–161.

42. John J. Mearsheimer, The Tragedy of Great Power Politics (New York: W.W. Norton, 2001), pp. 382, 399–400. On Japan pursuing a buck-passing strategy, see Jennifer M. Lind, “Pacifism or Passing the Buck? Testing Theories of Japanese Security Policy,” International Security 29 (Summer 2004), pp. 92–121.

43. Christopher P. Twomey, “The Dangers of Overreaching: International Relations Theory, the U.S.-Japan Alliance, and China,” in Self and Thompson, eds., An Alliance for Engagement, pp. 19–20, 26. Regarding the abandonment versus entrapment dilemma in alliances, see Glenn Snyder, “The Security Dilemma in Alliance,” World Politics 36 (July 1984), pp. 461–485.

44. Yuri Kase, “The Costs and Benefits of Japan's Nuclearization: An Insight into the 1968/70 Internal Report,” Nonproliferation Review 8 (Summer 2001), pp. 58–59, <cns.miis.edu/pubs/npr/vol08/82/82kase.pdf>

45. Hughes, “Why Japan Will Not Go Nuclear (Yet)”; and Kurt M. Campbell and Tsuyoshi Sunohara, “Japan: Thinking the Unthinkable,” in Campbell, Einhorn, and Reiss, eds., Nuclear Tipping Point, pp. 227–228.

46. Suzuki Manami, Kaku Tai-Kokuka suru Nihon: Heiwa Riyō to Kaku Busō Ron (A Japan Moving Toward a Nuclear Great Power: Peaceful Use and the Argument for Nuclear Armament) (Tokyo: Heibon Sha, 2006), p. 192.

47. Jeffrey W. Thompson and Benjamin L. Self, “Nuclear Energy, Space Launch Vehicles, and Advanced Technology: Japan's Prospects for Nuclear Breakout,” in Thompson and Self, eds., Japan's Nuclear Option, pp. 148–176.

48. Furukawa, “Making Sense of Japan's Nuclear Policy,” pp. 125–128.

49. Yukiya Amano, “A Japanese View of Nuclear Disarmament,” Nonproliferation Review 9 (Spring 2002), pp. 137–143, <cns.miis.edu/pubs/npr/vol09/91/91aman.pdf > ; and National Institute for Defense Studies Japan, East Asian Strategic Review 2004 (Tokyo: Japan Times, 2004), pp. 234–235. Consistent with the above Japanese view of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the National Academy of Sciences (of the United States) in fact argued that the CTBT would permit the United States to maintain technical reliability of its nuclear weapons by means other than nuclear testing that would be consistent with the U.S. Stockpile Stewardship Program that was established in 1994. See Committee on Technical Issues Related Ratification of the Comprehensive Nuclear Test Ban Treaty, Committee on International Security and Arms Control, National Academy of Sciences, Technical Issues Related to the Comprehensive Nuclear Test Ban Treaty (Washington, DC: National Academies Press, 2002), pp. 1–5, 19–34.

50. Eiichi Katahara, “Japan's Plutonium Policy: Consequences for Nonproliferation,” Nonproliferation Review 5 (Fall 1997), pp. 53–61, <cns.miis.edu/pubs/npr/vol05/51/kataha51.pdf.>

51. Suzuki, Kaku Tai-Kokuka suru Nihon, p. 34. See also the similar estimates in Thompson and Self, “Nuclear Energy, Space Launch Vehicles, and Advanced Technology,” pp. 162–164.

52. Thompson and Self, “Nuclear Energy, Space Launch Vehicles, and Advanced Technology,” pp. 165–166.

53. Suzuki, Kaku Tai-Kokuka suru Nihon, p. 133.

54. Shaun Burnie and Aileen Mioko Smith, “Japan's Nuclear Twilight Zone,” Bulletin of the Atomic Scientists 57 (May/June 2001), p. 59.

55. Eric Johnston, “Rokkasho Drawing Proliferation Flak: Multinational Controls Urged to Deter Nuclear Arms-Seeking Copycats,” Japan Times, November 15, 2005; and Eric Johnston, “Rokkasho Tests Break Plutonium Pledge, Activists Tell IAEA,” Japan Times, January 6, 2006.

56. Shinichi Ogawa and Michael Schiffer, “Japan's Plutonium Reprocessing Dilemma,” Arms Control Today 35 (October 2005), pp. 21–22.

57. Mike M. Mochizuki, “Japan's Search for Strategy,” International Security 8 (Winter 1983–84) pp. 166–168; and Mike M. Mochizuki, “The Soviet/Russian Factor in Japanese Security Policy,” in Tsuyoshi Hasegawa, Jonathan Haslam, and Andrew Kuchins, eds., Russia and Japan: An Unresolved Dilemma Between Distant Neighbors (Berkeley, CA: International and Area Studies, University of California at Berkeley, 1993), pp. 125–160.

58. During the late 1970s and early 1980s, North Korean agents abducted a number of Japanese citizens for the purpose, it is believed, of teaching Japanese language and culture to those training to become North Korean spies. The Japanese government now recognizes that 16 Japanese nationals had been kidnapped, but the North Korean government admitted in September 2002 to only 13 abductions and claimed that eight of them had died. The absence of clear proof and explanation of the exact circumstances of the purported deaths angered the Japanese public and derailed Japan's diplomatic engagement with North Korea. According to some accounts, the number of Japanese abducted by North Korea could be more than 70.

59. For an early analysis of this new round of debate, see Mitsuru Kurosawa, “Moving Beyond the Debate on a Nuclear Japan,” Nonproliferation Review 11 (Fall-Winter 2004), pp. 110–137.

60. The pro-nuclear weapons commentators include Fukuda Kazuya (professor of environmental information at Keio University), Hyōdō Nisohachi (independent military affairs analyst), Itō Kan (independent international politics analyst), Nakagawa Yatsuhiro (professor of international politics and political philosophy at Tsukuba University), Nakanishi Terumasa (professor of international politics at Kyoto University), Nishibe Susumu (conservative critic), and Sakurai Yoshiko (journalist and former television newscaster). Their arguments can be found in the following publications: Nakanishi Terumasa (ed.), “Nihon Kaku Busō” no Ronten (Arguments for “Japan's Nuclear Forces”) (Tokyo: PHP Kenkyūjō, 2006); Nakagawa Yatsuhiro, Nihon Kaku Busō no Sentaku (Japan's Nuclear Weapons Option) (Tokyo: Tokuma Shoten, 2004); Itō Kan, Chūgoku no “Kaku” ga Sekai o Seisu (The World Restrains China's Nuclear Forces) (Tokyo: PHP Kenkyūjō, 2006); and the August 2003 issue of Shokun!, the conservative nationalist monthly magazine.

61. Nakanishi Terumasa, “Nuclear Weapons for Japan,” Japan Echo 30 (October 2003), p. 52.

62. Nishibe Susumu, “Kaku Busōron ga Jishu Bō'ei e no Michi o Kiri Hiraku” (Nuclear Armament Opens the Way to Autonomous Defense), Seiron No. 375, pp. 86–98.

63. Nakanishi, “Nuclear Weapons for Japan,” p. 53.

64. Nakanishi, Fukuda Kazuya, “Nihon Kaku Busō Shikanai no ka” (Does Japan Have No Other Choice Besides Nuclear Armament?), Bungei Shunjū, June 2003, p. 182.

65. My thanks to Maria Rublee for sharing this point with me.

66. Teshima Ryūichi, et. al., “Dai Ni-ji Chōsen Sensō ka, Nihon Kaku Busō ka” (A Second Korean War or Japan's Nuclear Armament), Bungei Shunjū, December 2006, pp. 116–117; and Nakanishi Terumasa and Nishioka Chikara, “Anpō kara Hajimaru ‘Sengo kara no Dakkyaku’ to Nihon no Kaku Busō” (“Extrication from the Postwar” by Beginning with Security and Japan's Nuclear Armament), Seiron, December 2006, pp. 60–61.

67. Japanese commentators in this school of thought include Ken Jimbō (assistant professor at Keio University), Kamiya Matake (associate professor at the National Defense Academy), Kawakami Takashi (professor at Takushoku University), Kitaoka Shinichi (professor of political history at Tokyo University), Morimoto Satoshi (professor at Takushoku University and former diplomat), Nishihara Masashi (former president of the National Defense Academy), Okazaki Hisahiko (president of the Okazaki Institute and former Japanese ambassador to Thailand and Saudi Arabia), Sakurada Jun (lecturer at Tōyō Gakuen University), Shikata Toshiyuki (professor at Teikyo University and retired lieutenant general of the Ground Self-Defense Force), and Tanaka Akihiko (professor of international politics and director of the Institute of Oriental Culture at Tokyo University).

68. Masashi Nishihara, “North Korea's Trojan Horse,” Washington Post, August 14, 2003.

69. Tanaka Akihiko, “Kitai Dekinai Kita Chōsen no Kaku Haizetsu” (Elimination of North Korean Nuclear Weapons Cannot Be Expected), Ronza December 2006, pp. 42–43.

70. Hisahiko Okazaki, “Time to Change Our National Security Strategy,” Daily Yomiuri, April 23, 2006; Ishiba Shigeru, “Nit-chū Tatakawaba Katsu no wa Dotchi da?” (If Japan and China Fight, Which Side Would Win?), Bungei Shunjū, May 2006, pp. 138–140; Ken Jimbō, “Rethinking Japanese Security: New Concepts in Deterrence and Defense,” in Thompson and Self (eds.), Japan's Nuclear Option, pp. 33, 41–44; and Hiramatsu Shigeo, Chūgoku, Kaku Misairu no Hyōteki (China, Target of Nuclear Missiles) (Tokyo: Kadokawa, 2006).

71. Kamiya, “Nuclear Japan,” pp. 67–69; and Kitaoka Shinichi, “Kita no Kaku o Yokushi suru tame no Itsutsu no Sentakugi” (Five Choices to Deter North Korean Nuclear Weapons), Chūō Kōron, December 2006, pp. 39–40.

72. Tanaka, “Kitai Dekinai Kita Chōsen no Kaku Haizetsu,” p. 43.

73. Kawakami Takashi, “Nihon Kaku Busōron: ‘Fūin’ sareta Nihon Kaku Busōron o Toki Hanate” (Japan's Nuclear Armament Discussion: Liberate the “Sealed” Discussion of Nuclear Armament), Sekai Shūhō, January 16, 2007, pp. 6–10.

74. Sakurada Jun, “The Folly of Calls for Nuclear Armament,” Japan Echo 30 (August 2003), p. 42.

75. Commentators who advocate a more assertive non-nuclear policy include Asai Motofumi (president of the Hiroshima Peace Institute of Hiroshima City University), Ishizaka Kōichi (Rikkyō University), Kawasaki Akira (executive committee member of the international exchange NGO Peace Boat), Maeda Tetsuo (Tokyo International University), Sakamoto Yoshikazu (professor emeritus of international politics at Tokyo University), and Sugita Hiroki (journalist with Kyōdō News). Many of these commentators contribute to the pacifist-oriented monthly journal Sekai. After the North Korean nuclear tests, Sekai published the following joint statement: Ishizaka Kōichi, Kawasaki Akira, and Kim Pun-An, “Taiwa to Kaku Gunshuku Igai ni Michi wa nai” (There Is No Other Path Besides Dialogue and Nuclear Disarmament), Sekai December 2006, pp. 54–67.

76. Kurosawa, “Moving Beyond the Debate on a Nuclear Japan,” pp. 125–126.

77. Yoshikazu Sakamoto, “Defusing the Dangers of Nuclear Proliferation—North Korea: Threatening or Threatened?” Japan Times, January 1, 2007; and Sugita Hiroki, Hikaku no Sentaku (Non-Nuclear Choice) (Tokyo: Iwanami Shoten, 2005), pp. 236–238.

78. Weapons of Mass Destruction Commission, Weapons of Terror: Freeing the World of Nuclear, Biological and Chemical Weapons (Stockholm: Weapons of Mass Destruction Commission, 2006), <www.wmdcommission.org/files/Weapons_of_Terror.pdf.>

79. Ishizaka, Kawasaki, and Kim Pun, “Taiwa to Kaku Gunshuku Igai ni Michi wa nai,” pp. 65–66.

80. The notion of a “nuclear-weapon-free zone” has even had a few adherents among former and current Japanese officials. See for example, Kaneko, “Japan Needs No Umbrella,” pp. 50–51.

81. Kaneko, “Japan Needs No Umbrella,” pp. 50–51.

82. According to the November 11–12, 2006 Japanese public opinion survey conducted by the Yomiuri Shimbun, 74 percent did not expect the six-party talks to resolve the North Korean nuclear problem. Yomiuri Shimbun (Tokyo), November 20, 2006.

83. Yomiuri Shimbun (Tokyo), November 4, 2006; and Nihon Keizai Shimbun (Tokyo), November 14, 2006.

84. My thanks to Stephen Schwartz for pointing this out to me.

85. Mari Yamaguchi, “Defense Chief Says Nuclear Passage Through Japan Waters May Be Unavoidable,” Associated Press, November 26, 2006. Defense Minister Kyūma Fumio's statement provoked the opposition Social Democratic Party to seek a clarification to see if the government was indeed revising the three non-nuclear principles. Faced with this challenge, the Abe government retreated and reaffirmed the existing government position: “Any attempt to take nuclear weapons into our country, including the passage of a nuclear-armed U.S. military ship through our territorial waters, is subject to prior consultations (between Japan and the United States). In the event prior consultations are held, the government will invariably refuse the attempt.” Kyodo News, “Nukes Still Not Welcome: Cabinet,” Japan Times, December 21, 2006.

86. “Government May Ask U.S. for Details of Nuclear Defense Strategy,” Daily Yomiuri, March 21, 2007. The Japan Defense Agency was upgraded to the Ministry of Defense in January 2007.

87. Ogawa Shin'ichi of Japan's National Institute for Defense Studies, however, has argued that such retaliatory capabilities would not necessarily violate the spirit of Japan's exclusively defense-oriented policy if such capabilities were what are minimally required to defend the homeland. See Ogawa Shin'ichi, “Senshū Bō'ei to Tairyō Hakai Heiki Tōsai Dandō Misairu” (Exclusively Defensive Defense and WMD-Carrying Ballistic Missiles), NIDS Briefing Memo, January 2004, <www.nids.go.jp/dissemination/briefing/2004/pdf/200401_2.pdf.>

88. “North Korea's Nuclear Threat: SDF's Strike Capability—Time to Pick Up the Pike as Well as the Shield?” Daily Yomiuri, March 26, 2007.

89. Yomiuri Shimbun (Tokyo), October 16, 2006.

90. Mainichi Shimbun (Tokyo), November 27, 2006. In addition to the 61 percent who favored debating the nuclear issue even while opposing the possession of nuclear weapons, the Mainichi survey breakdown was as follows: 8 percent supported a nuclear debate with an eye toward acquiring nuclear weapons, 8 percent opposed a nuclear debate because such a debate could be misunderstood as Japan considering the acquisition of nuclear weapons, and 14 percent opposed a nuclear debate because such a debate could eventually lead to the acquisition of nuclear weapons. In other words, the Mainichi survey indicated that about 69 percent favor an open nuclear debate, while about 22 percent are opposed to such a debate.

91. Institute for International Policy Studies, “A Vision of Japan in the 21^st Century,” September 5, 2006, p. 6, <www.iips.org/National%20Vision.pdf.>

92. “Nakasone Proposes Japan Consider Nuclear Weapons,” Japan Times, September 6, 2006.

93. Yoshio Okawara, “Study of Nuclear Issue Demands Caution,” Japan Times, November 5, 2006.

94. Interestingly, however, former Prime Minister Nakasone Yasuhiro has continued to stress the need for Japan to have a nuclear debate as well as to develop an autonomous defense and diplomatic strategy so that Japan can be more frank with the United States. For example, see the following Nakasone article published in the conservative Japanese monthly Seiron: Nakasone Yasuhiro, “Abe Sōri ni Tsugu: Ima Koso Jishū Bō'ei—Gaikō o Kyōka se yo” (Proclaiming to Prime Minister Abe: Now Is the Time to Strengthen Autonomous Defense and Diplomacy), Seiron February 2007, pp. 57–64.

95. Hughes, “Why Japan Will Not Go Nuclear (Yet)”, pp. 92–95.

96. See for example, David Frum, “Mutually Assured Disruption,” New York Times, October 10, 2006, p. A25. Frum, a speechwriter for President George W. Bush in 2001–2002, argues for encouraging Japan to renounce the Treaty on the Non-Proliferation of Nuclear Weapons and create its own nuclear deterrent in order to punish China and North Korea and to dissuade Iran from going nuclear. But it is fair to say that this is a minority view even among American conservative policy analysts.

97. Ashley J. Tellis, India as a New Global Power: An Action Agenda for the United States (Washington, D.C.: Carnegie Endowment for International Peace, 2005), p. 33. For a more critical view of the U.S.-India nuclear energy agreement, see William C. Potter, “India and the New Look of U.S. Nonproliferation Policy,” Nonproliferation Review 12 (July 2005), pp. 343–354, <cns.miis.edu/pubs/npr/vol12/122/122potter.pdf.>

98. Associated Press, “Tokyo Tells India to Forsake Nukes and Join the NPT,” Japan Times, January 11, 2007.

99. For assessments of U.S. defense transformation by Japanese defense analysts, see for example Morimoto Satoshi, Bei-Gun Saihen to Zai-Nichi Bei-Gun (U.S. Military Transformation and U.S. Forces in Japan) (Tokyo: Bungei Shunjū, 2006); and Ebata Kensuke, Bei-Gun Saihen (Shin-pan) (U.S. Military Transformation (New Edition)) (Tokyo: Bijinesu Sha, 2006).

100. Associated Press, “Navy to Deploy Aegis Destroyer in Japan,” Japan Times, November 17, 2006; and “Sasebo May Host Site for Maintaining Interceptor Missiles,” Japan Times, December 5, 2006.

101. Jimbo, “Rethinking Japanese Security: New Concepts in Deterrence and Defense,” pp. 39–40.