The Fourth Wave in Deterrence Research

Abstract

Following the end of the Cold War and accelerating after 9/11, a new wave of research on deterrence has emerged. Building on an earlier characterization by Robert Jervis, this work is here designated the fourth wave. The fourth wave reflects efforts to grapple with the change from a relatively symmetrical situation of mutual deterrence that characterized the Cold War to the asymmetric threats that dominate the current security environment for the United States and many other states. Despite widespread doubts that have been expressed in public about whether the most threatening actors today are deterrable, the fourth wave is nearly unanimous in finding that deterrence remains relevant, even with respect to terrorism. Beyond this basic consensus, the fourth wave also includes vigorous debates, particularly regarding alternative strategies for dealing with WMD-seeking rogue states. Because few analysts expect deterrence to be foolproof, especially in dealing with non-state actors, much of the work has focused on finding ways to improve the prospects for deterrence at the margins. Overall, the most important result of the fourth wave has been to reveal the value of moving toward a broader concept of deterrence that incorporates non-nuclear and even non-military sources of leverage. Proposals to use information and discourse as bases for deterrence are especially innovative and worthy of further research.

ACKNOWLEDGEMENTS

The author thanks Caitlin Talmadge, Tim Crawford, Pat Morgan, and three anonymous reviewers for Contemporary Security Policy for helpful comments on earlier drafts of this paper. A preliminary draft of this paper was presented at the American Political Science Association annual meeting in Boston, Massachusetts, 28–31 August 2008.

Notes

Robert Jervis, ‘Deterrence Theory Revisited’, World Politics, Vol. 31, No. 2 (January 1979).

See, for example, ‘The Rational Deterrence Debate: A Symposium’, World Politics, Vol. 41, No. 2 (January1989).

Good examples include James Fearon, ‘Selection Effects and Deterrence’, International Interactions, Vol. 28, No. 1 (January–March 2002); Jeffrey Berejikian, ‘A Cognitive Theory of Deterrence’, Journal of Peace Research, Vol. 39, No. 2 (March 2002); Vesna Danilovic, When the Stakes are High (Ann Arbor, MI: University of Michigan Press, 2002); Timothy Crawford, Pivotal Deterrence (Ithaca: Cornell University Press, 2003); and Anne Sartori, Deterrence by Diplomacy (Princeton: Princeton University Press, 2005).

Keith B. Payne, Deterrence in the Second Nuclear Age (Lexington, KY: University Press of Kentucky, 1996); Naval Studies Board, National Research Council, Post-Cold War Conflict Deterrence (Washington, DC: National Academy Press,1997); Max G. Manwaring (ed.), Deterrence in the 21st Century (London: Frank Cass, 2001); Stephen J. Cimbala (ed.), Deterrence and Nuclear Proliferation in the Twenty-First Century (Westport, CT: Praeger, 2001).

Michael J. Powers, ‘Deterring Terrorism with CBRN Weapons: Developing a Conceptual Framework’, Occasional Paper 2, The Chemical and Biological Weapons Arms Control Institute, Washington, DC, February 2001.

See, for example, Ivo H. Daalder and James M. Lindsay, America Unbound: The Bush Revolution in Foreign Policy (Washington, DC: Brookings Institution Press, 2003), p. 125.

For an early call to expand deterrence theory beyond its traditional ‘focus on military tools’, see Ted Hopf, Peripheral Visions: Deterrence Theory and American Foreign Policy in the Third World, 1965–1990 (Ann Arbor, MI: Michigan University Press, 1994), p. 241. For more on the case for adopting a broader concept of deterrence, see Jeffrey W. Knopf, ‘Three Items in One: Deterrence as Concept, Research Program, and Political Issue’, in T.V. Paul, Patrick M. Morgan and James J. Wirtz (eds), Complex Deterrence: Strategy in the Global Age (Chicago: University of Chicago Press, 2009).

Smaller countries, of course, might see things differently.

See, for example, James H. Lebovic, ‘Deterrence and Homeland Security: A Defensive-Denial Strategy against Terrorists’, in Esther Brimmer (ed.), Five Dimensions of Homeland and International Security (Washington, DC: Center for Transatlantic Relations, Johns Hopkins University, 2008), pp. 106–7; Elbridge A. Colby, ‘Expanded Deterrence’, Policy Review, No. 149 (June/July 2008), p. 51.

Colin S. Gray, ‘Maintaining Effective Deterrence’, Strategic Studies Institute, US Army War College, Carlisle, PA, August 2003, p. v.

Lawrence Freedman, Deterrence (Cambridge: Polity Press, 2004), pp. 75–6. Others who make this point include C. Poppe et al., ‘Whither Deterrence? Final Report of the 2001 Futures Project’, Lawrence Livermore National Laboratory, Livermore, CA, 1 May 2002, pp. 17–18; Michael Quinlan, ‘Deterrence and Deterrability’, Contemporary Security Policy, Vol. 25, No. 1 (April 2004), p. 17; and James J. Wirtz, ‘Disarmament, Deterrence, and Denial’, Comparative Strategy, Vol. 24, No. 5 (December 2005), p. 384.

Patrick M. Morgan, Deterrence Now (Cambridge: Cambridge University Press, 2003), pp. 284–5. For similar arguments, see also Freedman, Deterrence (note 11), p. 116; Gray, ‘Maintaining Effective Deterrence’ (note 10), p. ix; and Klaus-Dieter Schwarz, ‘The Future of Deterrence’, SWP Research Paper, German Institute for International and Security Affairs, Berlin, June 2005, p. 36.

Alexander L. George and Richard Smoke, Deterrence in American Foreign Policy: Theory and Practice (New York: Columbia University Press, 1974); Robert Jervis, Perception and Misperception in International Politics (Princeton: Princeton University Press, 1976), Ch. 3; Richard Ned Lebow, Between Peace and War: The Nature of International Crisis (Baltimore: Johns Hopkins University Press, 1981); Janice Stein, ‘Deterrence and Reassurance’, in Philip Tetlock et al. (eds), Behavior, Society and Nuclear War, Vol. 2 (New York: Oxford University Press, 1991).

James H. Lebovic, Deterring International Terrorism and Rogue States: US National Security Policy after 9/11 (London: Routledge, 2007), pp. 2, 9.

Elbridge Colby, ‘Restoring Deterrence’, Orbis, Vol. 51, No. 3 (Summer 2007), pp. 417, 414; see also p. 421.

Lebovic, Deterring International Terrorism and Rogue States (note 14), p. 148; Colby, ‘Restoring Deterrence’ (note 15), pp. 420, 423.

For an explicit argument that Cold War-era deterrence research has relevance to efforts to apply deterrence in ‘the long war’, see Austin Long, Deterrence: From Cold War to Long War – Lessons from Six Decades of RAND Research (Santa Monica, CA: RAND, 2008).

Schwarz, ‘The Future of Deterrence’ (note 12); Robert Jervis, ‘Deterrence, Rogue States, and the U.S. Policy’, in Paul et al., Complex Deterrence (note 7), p. 141.

For good summations of their thinking, see Keith B. Payne, ‘The Fallacies of Cold War Deterrence and a New Direction’, and Colin S. Gray, ‘The Reformation of Deterrence: Moving On’, both in Comparative Strategy, Vol. 22, No. 5 (December 2003).

Keith B. Payne, The Great American Gamble: Deterrence Theory and Practice from the Cold War to the Twenty-First Century (Fairfax, VA: National Institute Press, 2008).

Gray, ‘The Reformation of Deterrence’ (note 19), p. 450; Keith B. Payne, ‘Bush Administration Strategic Policy: A Reality Check’, Journal of Strategic Studies, Vol. 28, No. 5 (October 2005), p. 780.

Derek D. Smith, Deterring America: Rogue States and the Proliferation of Weapons of Mass Destruction (Cambridge: Cambridge University Press, 2006), p. 7; Gerard Alexander, ‘International Relations Theory Meets World Politics’, in Stanley A. Renshon and Peter Suedfeld (eds), Understanding the Bush Doctrine (New York: Routledge, 2007), p. 49.

Derek D. Smith, ‘Deterrence and Counterproliferation in an Age of Weapons of Mass Destruction’, Security Studies, Vol. 12, No. 4 (Summer 2003), p. 166; Payne, ‘The Fallacies of Cold War Deterrence’ (note 19), p. 421.

Adam Garfinkle, ‘Culture and Deterrence’, Foreign Policy Research Institute E-Notes, 25 August 2006.

A.R. Knott, ‘Does 9/11 Mark the End of Deterrence and the Birth of “Detercion”?’, Defence Studies, Vol. 4, No. 1 (Spring 2004), p. 45; for a similar argument, see also Gray, ‘Maintaining Effective Deterrence’ (note 10), p. 27.

Richard K. Betts, ‘Striking First: A History of Thankfully Lost Opportunities’, Ethics and International Affairs, Vol. 17, No. 1 (Spring 2003); Jeffrey Record, ‘Nuclear Deterrence, Preventive War, and Counterproliferation’, Policy Analysis, No. 519, Cato Institute, 8 July 2004; Freedman, Deterrence (note 11), p. 99; Dan Reiter, ‘Preventive War and Its Alternatives: The Lessons of History’, Strategic Studies Institute, US Army War College, Carlisle, PA, April 2006; David Holloway, ‘Deterrence, Preventive War, and Preemption’, in George Bunn and Christopher F. Chyba (eds), U.S. Nuclear Weapons Policy: Confronting Today's Threats (Stanford, CA: Center for International Security and Cooperation, 2006); Jeffrey W. Knopf, ‘Deterrence or Preemption?’, Current History, Vol. 105, No. 694 (November 2006); Jeffrey W. Knopf, ‘Wrestling with Deterrence: Bush Administration Strategy after 9/11’, Contemporary Security Policy, Vol. 29, No. 2 (August 2008), pp. 248–53; Lebovic, Deterring International Terrorism and Rogue States (note 14), Ch. 3; Robert S. Litwak, Regime Change: U.S. Strategy through the Prism of 9/11 (Baltimore: Johns Hopkins University Press, 2007), pp. 64–86. There are other studies that are even more detailed in their analysis of past efforts at preemption and preventive war, but they do not explicitly compare these against deterrence as alternative options for US policy. See Lyle J. Goldstein, Preventive Attack and Weapons of Mass Destruction: A Comparative Historical Analysis (Stanford, CA: Stanford University Press, 2006); Karl P. Mueller et al., Striking First: Preemptive and Preventive Attack in U.S. National Security Policy (Santa Monica, CA: RAND, 2006).

Thomas C. Schelling, Arms and Influence (New Haven, CT: Yale University Press, 1966), p. 74.

Robert L. Jervis, ‘The Confrontation between Iraq and the US: Implications for the Theory and Practice of Deterrence’, European Journal of International Relations, Vol. 9, No. 2 (June 2003), p. 325.

Jasen J. Castillo, ‘Nuclear Terrorism: Why Deterrence Still Matters’, Current History, Vol. 102, No. 668 (December 2003), pp. 428, 431; Record, ‘Nuclear Deterrence, Preventive War, and Counterproliferation’ (note 26), p. 16; Schwarz, ‘The Future of Deterrence’ (note 12), p. 21; Knopf, ‘Deterrence or Preemption?’ (note 26), p. 396; Knopf, ‘Wrestling with Deterrence’ (note 26), p. 253; Litwak, Regime Change (note 26), p. 94.

Smith, Deterring America (note 22), pp. 110, 115, 120; Gray, ‘The Reformation of Deterrence’ (note 19), p. 452.

Smith, Deterring America (note 22), pp. 39, 41.

Alexander, ‘International Relations Theory Meets World Politics’ (note 22), p. 52. Making a similar observation but with more balanced language, Patrick Clawson and Michael Eisenstadt conclude that in the case of Iran, ‘Deterrence is not some easy, low-risk alternative that is obviously preferable to preventive military action’. Patrick Clawson and Michael Eisenstadt (eds), Deterring the Ayatollahs: Complications in Applying Cold War Strategy to Iran, Policy Focus #72 (Washington, DC: Washington Institute for Near East Policy, 2007), p. 34.

Knopf, ‘Wrestling with Deterrence’ (note 26), p. 251.

Lebovic, Deterring International Terrorism and Rogue States (note 14), pp. 2, 71, emphasis in original.

Poppe et al., ‘Whither Deterrence?’ (note 11), p. 7; Gray, ‘Maintaining Effective Deterrence’ (note 10), pp. 21, 31; Jervis, ‘Deterrence, Rogue States, and the Bush Administration’ (note 18).

Michael O. Wheeler, ‘Nuclear Deterrence Issues in the Post-September 11 World: An American Perspective’, in Nuclear Issues in the Post-September 11 Era, Recherches & Documents No. 30, Fondation pour la Recherche Strategique, March 2003, p. 76; Gray, ‘Maintaining Effective Deterrence’ (note 10), pp. ix, 9, 33; Payne, ‘The Fallacies of Cold War Deterrence’ (note 19), pp. 422–3; Quinlan, ‘Deterrence and Deterrability’ (note 11), p. 12; Freedman, Deterrence (note 11), pp. 58–9; Litwak, Regime Change (note 26), pp. 8, 81, 88; Jerrold M. Post, ‘Deterrence in an Age of Asymmetric Rivals’, in Renshon and Suedfeld, Understanding the Bush Doctrine (note 22), p. 158.

See, for example, US Department of Defense, Quadrennial Defense Review Report, 6 February 2006, preface, p. vi.

Jacquelyn K. Davis et al., ‘Updating U.S. Deterrence Concepts and Operational Planning’, Institute for Foreign Policy Analysis, Cambridge, MA, February 2009, pp. 5, 15.

Jeffrey S. Lantis, ‘Strategic Culture and Tailored Deterrence: Bridging the Gap between Theory and Practice’, Contemporary Security Policy, Vol. 30, No. 3 (December 2009), p. 476.

See esp. the essays in Karl-Heinz Kamp and David S. Yost (eds), NATO and 21st Century Deterrence, NDC Forum Paper 8 (Rome: NATO Defense College, May 2009). There has been criticism that the new concept of deterrence developed in the Bush years was actually too broad. Critics suggest that it does not provide sufficient guidance on how to prioritize which threats to deter or how to choose which of the range of military and non-military tools available should actually be employed. This seems less a critique of a broad approach, however, than a recognition that details of implementation still need to be worked out. See Charles D. Lutes, ‘Combating WMD Threats’, p. 85, and Christopher J. Lamb et al., ‘Transforming Defense Strategy and Policy’, pp. 284–5, both in Stephen J. Flanagan and James A. Schear (eds), Strategic Challenges: America's Global Security Agenda (Washington, DC: National Defense University Press; Dulles, VA: Potomac Books, 2008).

Knopf, ‘Wrestling with Deterrence’ (note 26), pp. 253–6.

Morgan, Deterrence Now (note 12), pp. 66–7.

For some thoughtful initial assessments that focus mainly on the challenges in implementing tailored deterrence, see M. Elaine Bunn, ‘Can Deterrence Be Tailored?’, Strategic Forum, No. 225 (January 2007); Kamp and Yost, NATO and Tailored Deterrence (note 40); David S. Yost, ‘NATO and Tailored Deterrence: Key Workshop Findings in 2007–2008’, Strategic Insights, Vol. 8, No. 4 (September 2009); and Lantis, ‘Strategic Culture and Tailored Deterrence’ (note 39).

Glenn H. Synder, ‘Deterrence by Denial and Punishment’, Research Monograph No. 1, Princeton University Center of International Studies, 1959; Glenn Snyder, Deterrence and Defense: Toward a Theory of National Security (Princeton, NJ: Princeton University Press, 1961).

Paul K. Davis and Brian Michael Jenkins, Deterrence and Influence in Counterterrorism: A Component in the War on al Qaeda (Santa Monica, CA: RAND, 2002), p. xi, emphasis in original; see also pp. 13–16.

Alexander L. George, ‘The Need for Influence Theory and Actor-Specific Behavioral Models of Adversaries’, Comparative Strategy, Vol. 22, No. 5 (December 2003), p. 465.

Neil J. Smelser and Faith Mitchell (eds), Discouraging Terrorism: Some Implications of 9/11, National Research Council study (Washington, DC: National Academies Press, 2002).

Wyn Q. Bowen, ‘Deterrence and Asymmetry: Non-State Actors and Mass Casualty Terrorism’, Contemporary Security Policy, Vol. 25, No. 1 (April 2004), pp. 58, 65, 67.

See, for example, Davis and Jenkins, Deterrence and Influence in Counterterrorism (note 45), pp. 19–20.

Colby, ‘Restoring Deterrence’ (note 15), p. 421; see also Davis and Jenkins, Deterrence and Influence (note 45), pp. 10, 60.

Davis and Jenkins, Deterrence and Influence in Counterterrorism (note 45), p. 5.

In theory, the United States could threaten to increase the intensity of its efforts to eradicate al Qaeda's leadership if there is a future mass-casualty attack on US soil, while implicitly promising not to intensify its efforts otherwise, but it is hard to imagine that such a fine-grained message would have much impact on al Qaeda's behaviour.

Robert F. Trager and Dessislava P. Zagorcheva, ‘Deterring Terrorism: It Can Be Done’, International Security, Vol. 30, No. 3 (Winter 2005/2006).

Davis and Jenkins, Deterrence and Influence in Counterterrorism (note 45), pp. xii, 15; see also p. 59.

C. Poppe et al., ‘Whither Deterrence?’ (note 11), p. 24.

Robert W. Anthony, ‘Deterrence and the 9-11 Terrorists’, Institute for Defense Analyses, Alexandria, VA, May 2003.

Esther Brimmer and Daniel S. Hamilton, ‘Introduction: Five Dimensions of Homeland and International Security’, in Brimmer, Five Dimensions (note 9), pp. 3, 10.

Davis and Jenkins, Deterrence and Influence in Counterterrorism (note 45), pp. xiv–xv.

Brad Roberts, ‘Deterring Terrorism: Terrorist Campaigns and Prolonged Wars of Mutual Coercion’, in Institute for Defense Analyses, Deterring Terrorism: Exploring Theory and Methods, August 2002 (For Official Use Only); Gordon Drake, Warrick Paddon and Daniel Ciechanowski, ‘Can We Deter Terrorists from Employing Weapons of Mass Destruction on the U.S. Homeland?’, John F. Kennedy School of Government, National Security Program Discussion Paper Series, 2003; Bowen, ‘Deterrence and Asymmetry’ (note 48); David P. Auerswald, ‘Deterring Nonstate WMD Attacks’, Political Science Quarterly, Vol. 121, No. 4 (Winter 2006/2007); S. Paul Kapur, ‘Deterring Nuclear Terrorists’, in Paul et al., Complex Deterrence (note 7).

Report by the National War College Student Task Force on Combating Terrorism, Combating Terrorism in a Globalized World (November 2002), pp. 45, xxii. The report is remarkable because, as a result of this effort, the Student Task Force was invited to participate in drafting the Bush administration's first-term National Strategy to Combat Terrorism, and significant portions of the Student Task Force recommendations were incorporated into the National Strategy.

Gray, ‘Maintaining Effective Deterrence’ (note 10), p. viii; see also p. 28. For another example of a senior scholar who makes this point see Freedman, Deterrence (note 11), pp. 123–4.

James M. Smith and Brent J. Talbot, ‘Terrorism and Deterrence by Denial’, in Paul R. Viotti, Michael A. Opheim and Nicholas Bowen (eds), Terrorism and Homeland Security: Thinking Strategically about Policy (Boca Raton, FL: CRC Press, 2008).

Lee E. Dutter and Ofira Seliktar, ‘To Martyr or Not to Martyr: Jihad Is the Question, What Policy Is the Answer?’, Studies in Conflict & Terrorism, Vol. 30, No. 5 (May 2007), pp. 435–6. Despite this observation, the authors (p. 438) still see tactical deterrence by denial as likely to be the most feasible approach.

Alex S. Wilner, ‘Deterring the Undeterrable: Coercion, Denial, and Delegitmization in Counterterrorism’, Journal of Strategic Studies, forthcoming (Summer 2010).

Lebovic, Deterring International Terrorism and Rogue States (note 14), p. 182; Knopf, ‘Wrestling with Deterrence’ (note 26), pp. 256–7.

Joseph Lepgold, ‘Hypotheses on Vulnerability: Are Terrorists and Drug Dealers Coercable?’, in Lawrence Freedman (ed.), Strategic Coercion: Concepts and Cases (New York: Oxford University Press, 1998), pp. 136, 145.

Doron Almog, ‘Cumulative Deterrence and the War on Terrorism’, Parameters, Vol. 34, No. 4 (Winter 2004/2005).

Gerald M. Steinberg, ‘Rediscovering Deterrence after September 11, 2001’, Jerusalem Letter/Viewpoints, No. 467, Jerusalem Center for Public Affairs, 2 December 2001, available at www.jcpa.org/jl/vp467.htm (accessed 11 August 2003).

Ariel Merari, ‘Deterring Fear: Government Responses to Terrorist Attacks’, Harvard International Review (Winter 2002), pp. 29–30; Shmuel Bar, ‘Deterring Terrorists: What Israel Has Learned’, Policy Review, No. 149 (June/July 2008), quote at p. 40, n. 6; Amos Malka, ‘Israel and Asymmetrical Deterrence’, Comparative Strategy, Vol. 27, No. 1 (January/February 2008), quote at p. 17.

Bar, ‘Deterring Terrorists’ (note 69), p. 42.

Uri Fisher, ‘Deterrence, Terrorism, and American Values’, Homeland Security Affairs, Vol. 3, No. 1 (February 2007).

Davis and Jenkins, Deterrence and Influence in Counterterrorism (note 45), pp. 27–8.

Jonathan Schachter, The Eye of the Believer: Psychological Influences on Counter-Terrorism Policy-Making (Santa Monica, CA: RAND, 2002), pp. 113–15.

Bowen, ‘Deterrence and Asymmetry’ (note 48), p. 63; Auerswald, ‘Deterring Nonstate WMD Attacks’ (note 59), p. 551; Lebovic, Deterring International Terrorism and Rogue States (note 14), p. 126; Lewis A. Dunn, ‘Deterrence Today: Roles, Challenges and Responses’, IFRI Proliferation Papers No. 19, French Institute of International Relations, Paris, Summer 2007, p. 24. For a contrary position, see Colby, ‘Expanded Deterrence’ (note 15), p. 53. But Colby just asserts that retaliatory threats will do more to reduce than to provoke hostile behaviour, without explaining how to keep threats against Muslim populations or religious symbols from working to al Qaeda's advantage.

Roberts, ‘Deterring Terrorism’ (note 59), p. IV-32; Auerswald, ‘Deterring Nonstate WMD Attacks’ (note 59), p. 548; Lebovic, Deterring International Terrorism and Rogue States (note 14), p. 125.

Scott Helfstein et al., ‘Terrorism, Deterrence and Nuclear Weapons’, White Paper Prepared for the Secretary of Defense Task Force on DoD Nuclear Weapons Management, Combating Terrorism Center, US Military Academy, West Point, NY, 31 October 2008, p. 32; Adam Garfinkle, ‘Does Nuclear Deterrence Apply in the Age of Terrorism?’, Footnotes: The Newsletter of FPRI's Wachman Center, Vol. 14, No. 10, Foreign Policy Research Institute (May 2009).

Report by the National War College Student Task Force on Combating Terrorism (note 60), p. 42.

Alex S. Wilner, ‘Targeted Killings in Afghanistan: Measuring Coercion and Deterrnce in Counterterrorism and Counterinsurgency’, Studies in Conflict and Terrorism, Vol. 33, No. 4 (April 2010).

Roberts, ‘Deterring Terrorism’ (note 59), p. IV-55.

Report by the National War College Student Task Force on Combating Terrorism (note 60), p. 44.

Bruno S. Frey, Dealing with Terrorism – Stick or Carrot? (Cheltenham: Edward Elgar, 2004). Frey is one of the few fourth-wave analysts who rejects the use of deterrence against terrorism; he advocates reliance on positive incentives instead. While his proposal to improve the peaceful alternatives to terrorism makes sense (and is compatible with a deterrence strategy), other recommendations in the book are peculiar to say the least. For example, Frey proposes decentralizing society by dispersing government and population so as to reduce the number of high-value targets for terrorist attack. Whatever its theoretical merit, this is a practical non-starter.

Daniel Whiteneck, ‘Deterring Terrorists: Thoughts on a Framework’, Washington Quarterly, Vol. 28, No. 3 (Summer 2005); Colby, ‘Expanded Deterrence’ (note 15); Kapur, ‘Deterring Nuclear Terrorists’ (note 59).

Whiteneck, ‘Deterring Terrorists’ (note 82), pp. 194, 196; Colby, ‘Expanded Deterrence’ (note 15), p. 49; Kapur, ‘Deterring Nuclear Terrorists’ (note 59).

Colby, ‘Expanded Deterrence’ (note 15).

Helfstein et al., ‘Terrorism, Deterrence and Nuclear Weapons’ (note 76), pp. 3–5, 18–21.

Roberts, ‘Deterring Terrorism’ (note 59), pp. IV-23–IV-24; Quinlan, ‘Deterrence and Deterrability’ (note 11), pp. 15–16; Jonathan Stevenson, ‘Reviving Deterrence’, in Brimmer (ed.), Five Dimensions (note 9), p. 51. In an important forerunner to these suggestions from before 9/11, Joseph Lepgold noted that efforts to delegitimize terrorist methods or political objectives could have deterrent effects, but he did not elaborate on how this might be done. ‘Hypotheses on Vulnerability’ (note 66), p. 144.

Lewis A. Dunn, ‘Can al Qaeda Be Deterred from Using Nuclear Weapons?’, Occasional Paper 3, Center for the Study of Weapons of Mass Destruction (Washington, DC: National Defense University Press, July 2005), pp. 2, 11.

Ibid., p. 24. See also Dunn, ‘Deterrence Today’ (note 74), pp. 20–2.

Brad Roberts, ‘Deterrence and WMD Terrorism: Calibrating its Potential Contributions to Risk Reduction’, Institute for Defense Analyses, Alexandria, VA, June 2007, p. 18.

Helfstein et al., ‘Terrorism, Deterrence and Nuclear Weapons’ (note 76), p. 30.

Wilner, ‘Deterring the Undeterrable’ (note 64).

Evan Braden Montgomery, Nuclear Terrorism: Assessing the Threat, Developing a Response (Washington, DC: Center for Strategic and Budgetary Assessments, 2009), pp. 68–72, quote at p. 70. This letter is also cited by Stevenson, ‘Reviving Deterrence’, p. 50, and Lewis A. Dunn, ‘Influencing Terrorists’ Acquisition and Use of Weapons of Mass Destruction: Exploring a Possible Strategy', in Kamp and Yost, NATO and 21st Century Deterrence (note 40), pp. 135–6.

Garfinkle, ‘Does Nuclear Deterrence Apply?’ (note 76).

Kapur, ‘Deterring Nuclear Terrorists’ (note 59). Montgomery notes that all efforts to secure or reduce the availability of nuclear materials add to deterrence by denial, with the ultimate goal being to convince terrorists that obtaining a nuclear device is simply not a realistic option. Nuclear Terrorism (note 92), p. 72.

Robin M. Frost, ‘Nuclear Terrorism after 9/11’, Adelphi Papers, No. 378 (Abingdon: Routledge, December 2005), p. 9; Auerswald, ‘Deterring Nonstate WMD Attacks’ (note 59), p. 555; Litwak, Regime Change (note 26), p. 304; Vera L. Zakem and Danielle R. Miller, ‘Stop or Else: Basic Concepts to Deter Violent Non-State Actors’, in Russell D. Howard and James J.F. Forest (eds), Weapons of Mass Destruction and Terrorism (New York: McGraw Hill, 2008), p. 351.

Jervis, ‘The Confrontation between Iraq and the US’ (note 28), p. 332, n. 8; Castillo, ‘Nuclear Terrorism’ (note 29), p. 429; Record, ‘Nuclear Deterrence, Preventive War, and Counterproliferation’ (note 26), p. 20; Frost, ‘Nuclear Terrorism after 9/11’ (note 95), p. 64; Auerswald, ‘Deterring Nonstate WMD Attacks’ (note 59), p. 555; Knopf, ‘Wrestling with Deterrence’ (note 26), p. 250.

Castillo, ‘Nuclear Terrorism’ (note 29), p. 429; Frost, ‘Nuclear Terrorism after 9/11’ (note 95), pp. 64, 70; Litwak, Regime Change (note 26), p. 304; Knopf, ‘Wrestling with Deterrence’ (note 26), p. 250; Zakem and Miller, ‘Stop or Else’ (note 95), p. 352.

Whiteneck, ‘Deterring Terrorists’ (note 82), pp. 192–3.

Alexander, ‘International Relations Theory Meets World Politics’ (note 22), p. 49; Matthew Phillips, ‘Uncertain Justice for Nuclear Terror: Deterrence of Anonymous Attacks through Attribution’, Orbis, Vol. 51, No. 3 (Summer 2007), p. 439.

For an overview of nuclear forensics intended for a general audience, see Michael Miller, ‘Nuclear Attribution as Deterrence’, Nonproliferation Review, Vol. 14, No. 1 (March 2007).

Michael A. Levi, ‘Deterring Nuclear Terrorism’, Issues in Science and Technology (Spring 2004), available at www.issues.org/20.3/levi.html (accessed 5 July 2005); see also Graham Allison, ‘Nuclear Accountability’, Technology Review (July 2005). Jay Davis of Livermore Lab (and a former director of the Defense Threat Reduction Agency) was another early proponent of investing in nuclear forensics. Like Levi, he implied that deterrence would flow automatically from forensics, but he did acknowledge that there are technical and organizational challenges in attribution. See Jay Davis, ‘The Grand Challenges of Counter-Terrorism’, Center for Global Security Research, Lawrence Livermore National Laboratory, 2001, available at cgsr.llnl.gov/CGSR/Document.jsp?T = D&ID = 28 (accessed 14 November 2008), and ‘The Attribution of WMD Events’, Journal of Homeland Security (April 2003).

Levi, ‘Deterring Nuclear Terrorism’ (note 101); Robert L. Gallucci, ‘Averting Nuclear Catastrophe: Contemplating Extreme Responses to U.S. Vulnerability’, Annals of the American Academy of Political and Social Science, No. 607 (September 2006), pp. 57–8; Miller, ‘Nuclear Attribution as Deterrence’ (note 100), pp. 52, 54; Caitlin Talmadge, ‘Deterring a Nuclear 9/11’, Washington Quarterly, Vol. 30, No. 2 (Spring 2007), p. 29.

Talmadge, ‘Deterring a Nuclear 9/11’ (note 102).

Miller, ‘Nuclear Attribution as Deterrence’ (note 100), pp. 33, 52; Talmadge, ‘Deterring a Nuclear 9/11’ (note 102), pp. 30–1; Kapur, ‘Deterring Nuclear Terrorists’ (note 59), p. 124; Michael A. Levi, Deterring State Sponsorship of Nuclear Terrorism, Council Special Report No. 39 (New York: Council on Foreign Relations, September 2008), p. 27.

Anders Corr, ‘Deterrence of Nuclear Terrorism: A Negligence Doctrine’, Nonproliferation Review, Vol. 12, No. 1 (March 2005).

Gallucci, ‘Averting Nuclear Catastrophe’ (note 102), pp. 57–8 (Gallucci also published an earlier, slightly shorter version of the article in Harvard International Review, Vol. 26, No. 4 [Winter 2005]; this and subsequent references are to the 2006 article in Annals, cited above).

Colby, ‘Expanded Deterrence’ (note 15).

Gallucci, ‘Averting Nuclear Catastrophe’ (note 102), p. 58, emphasis in original.

Corr, ‘Deterrence of Nuclear Terrorism’ (note 105), p. 129, emphasis in original.

Whiteneck, ‘Deterring Terrorists’ (note 82), pp. 191–2, 198; Gallucci, ‘Averting Nuclear Catastrophe’ (note 102), p. 57; Dunn, ‘Influencing Terrorists’ Acquisition' (note 92), p. 138.

Corr, ‘Deterrence of Nuclear Terrorism’ (note 105), p. 136. Others who advocate threatening regime change as a way to deter states from transferring WMD to terrorists include Fisher, ‘Deterrence, Terrorism and American Values’ (note 71), p. 6; and Knopf, ‘Wrestling with Deterrence’ (note 26), p. 255.

Whiteneck, ‘Deterring Terrorists’ (note 82), p. 191.

Miller, ‘Nuclear Attribution as Deterrence’ (note 100), p. 48.

Gallucci, ‘Averting Nuclear Catastrophe’ (note 102), p. 58; Litwak, Regime Change (note 26), p. 318; Colby, ‘Expanded Deterrence’ (note 15), p. 57.

Phillips, ‘Uncertain Justice for Nuclear Terror’ (note 99), p. 442.

See also, for example, Levi, Deterring State Sponsorship (note 104), p. 18.

Levi, Deterring State Sponsorship (note 104). Montgomery (Nuclear Terrorism, note 92, p. 91) also warns against threatening military retaliation after nuclear leakage for similar reasons.

Auerswald, ‘Deterring Nonstate WMD Attacks’ (note 59), pp. 557–9.

Ibid., pp. 561, 565, 567.

Ibid., pp. 567–8.

Anne-Marie Slaughter and Thomas Wright, ‘Punishment to Fit the Nuclear Crime’, Washington Post, 2 March 2007, p. A13.

Smith, Deterring America (note 22), Part II; Graham Allison, ‘Deterring Kim Jong Il’, Washington Post, 27 October 2006, p. A23. Keith Payne also seems to draw this inference, but his wording is ambiguous. He could be making the related point that having allowed Iran to cross a series of red-lines without significant consequences, the United States has undermined its own deterrent credibility. ‘Deterring Iran: The Values at Stake and the Acceptable Risks’, in Clawson and Eisenstadt, Deterring the Ayatollahs (note 21), p. 3. But it is unlikely that getting away with adding a few centrifuges will lead Iran to believe it could launch a nuclear attack with impunity.

The importance of clearly defining and communicating red-lines is also stressed by Michael S. Gerson, ‘Concepts of Deterrence in the 21st Century: Some Things Old, Some Things New’, in Kamp and Yost, NATO and 21st Century Deterrence (note 40), pp. 168, 170.

See, for example, Gregory F. Giles, ‘Waging Deterrence against Iran’, p. 118, and Jonathan Trexel, ‘Concepts for Deterrence Operations’, pp. 198–9, both in Kamp and Yost, NATO and 21st Century Deterrence (note 40).