The German Invasion of Norway, 1940: The Operational Intelligence Dimension

Abstract

While many analyses of the 9 April 1940 invasion of Norway have looked at the successful interplay of German air, sea and land components, the part performed by intelligence has largely received only cursory attention. This article seeks to redress this, and investigates the pivotal role intelligence played in the planning, preparation, and carrying out of Weserübung. The study examines the dearth of relevant information in the early planning stage; the subsequent accumulation of military assessments of Norway's defensive capabilities; the process of denying London and Oslo intelligence regarding Berlin's intentions; the significance of Danish and Norwegian airfields to the operation; and the importance of maritime reconnaissance and wireless intercepts in monitoring the disposition of the Royal Navy. Although primarily concerned with German intelligence gathering and utilisation, British efforts, including the potential impact of Ultra, are also considered.

ACKNOWLEDGEMENTS

I would like to thank Dr Andrew Conway of the University of Canterbury, New Zealand, for his helpful comments and criticisms.

Notes

Adam Claasen is a Lecturer in Modern History, International Relations and Politics at Massey University, Auckland, New Zealand. As well as teaching papers on politics, international relations, and German history, he also lectures on the Russo-Chechen Wars and the Arab–Israeli conflict. His most recent publication is Hitler's Northern War: The Luftwaffe's Ill-fated Campaign, 1940–45 (Lawrence: University Press of Kansas 2001), in which he examines the role of German airpower in Norway from the 1940 invasion until the war's end.

M. Domarus, Hitler, Reden und Proklamation, 1932 bis 1945. Teil II Untergang, Bd. 3, 1939–1940 (Leonberg: Pamminger & Partner 1988) p.1523.

US Department of State, Documents on German Foreign Policy, 1918–1945, Series D, Vol. 7, Doc. 525 (Washington DC: US Government Printing Office 1956) pp.502–3.

E.F. Ziemke, ‘The German Decision to Invade Norway and Denmark’, in K.R. Greenfield (ed.), Command Decisions (Washington DC: Office of the Chief of Military History United States Army 1960) p.50.

For a general discussion of Norwegian neutrality, see J. Andenaes, O. Riste and M. Skodvin, Norway and the Second World War (Oslo: Johan Grundt Tanum Forlag 1966) pp.9–13; and M. Skodvin, ‘Aspects of Neutrality: The Norwegian Experience’, in K. Rommetveit (ed.), Narvik 1940: Five-Nation War in the High North (Oslo: Institutt for Forsvarsstudier 1991) pp.15–23. A more detailed examination of the complexities surrounding Norwegian neutrality is presented in M. Skodvin, ‘Norwegian neutrality and the question of credibility’, Scandinavian Journal of History 2 (1977) pp.123–45.

An appraisal of the decision-making process appears in A. Claasen, ‘Blood and Iron, and der Geist des Atlantiks: Assessing Hitler's Decision to invade Norway’, Journal of Strategic Studies 20/3 (Sept. 1997) pp.71–96

R. Karlbom, ‘Sweden's Iron Ore Exports to Germany, 1933–1944’, Scandinavian Economic History Review 13/1–2 (1965) pp.65–93; A.S. Milward, ‘Could Sweden have Stopped the Second World War?’, Scandinavian Economic History Review 15/2 (1967) pp.127–38; J. Jäger, ‘Sweden's Iron Ore Exports to Germany, 1933–1944: A Reply to Rolf Karlbom's Article on the Same Subject’, Scandinavian Economic History Review 15/1–2 (1967) pp.139–47; M. Fritz, German Steel and Swedish Iron Ore, 1939–1945 (Göteborg: Institute of Economic History of Göteborg University 1974).

Discussions of how Scandinavia fitted into German naval considerations can be found in C. Gemzell's two works: Raeder, Hitler und Skandinavien: Der Kampf für einen maritimen Operationsplan (Lund: CWK Gleerup 1965); and Organization, Conflict, and Innovation: A Study of German Naval Strategic Planning, 1888–1940 (Lund: Esselte Studium 1973). See also M. Salewski's first volume of the standard work on the German Navy in this period, Die deutsche Seekriegsleitung 1935–45. Bd. I: 1935–1941 (Frankfurt: Bernard & Graefe 1970); and H.-M. Ottmer's more recent addition to historiography, ‘Skandinavien in den marinestrategischen Planungen der Reichs-bzw. Kriegsmarine’, in R. Bohn et al. (eds), Neutralität und totalitäre Aggression: Nordeuropa und die Großmächte im Zweiten Weltkrieg (Stuttgart: Franz Steiner 1991) pp.49–72.

For Studie Nord: National Archives, Washington, DC [hereafter NA] T1022/1818: Lagebetrachtung zur Studie ‘Nord’, pp.9–10; E.F. Ziemke, The German Northern Theater of Operations, 1940–1945. Pamplet No. 20–271 (Washington, DC: Department of the Army 1959) pp.12–13; M. Salewski, ‘Germany and North Norway: Strategy and Ideology’, in Rommetveit (note 4) pp.15–23.

USAF Historical Support Office, Bolling Air Force Base, Washington, DC [hereafter USAFHSO] K113.107–171: A.L. Nielsen, ‘The collection and evaluation of intelligence for the German Air Force High Command’ (1955), p.113.

Ibid.

Ziemke, The German Northern Theater, p.15; for lack of military maps see W. Hubatsch, ‘Weserübung’. Die deutsche Besetzung von Dänemark und Norwegen 1940 (Göttingen: Musterschmidt Verlag 1960) p.40.

USAFHSO K113.107–171: Nielsen (note 9) p.11.

D. Kahn, Hitler's Spies: German Military Intelligence in World War II (NY: Macmillan 1978) p.119.

USAFHSO K113.107–171: Nielsen (note 9) p.115.

W. Hubatsch, Hitlers Weisungen für die Kriegführung 1939–1945: Dokumente des Oberkommandos der Wehrmacht (Koblenz: Bernard & Graefe 1983) pp.47–9.

O.U. Munthe-Kaas, ‘The Campaign in Norway in 1940 and the Norwegian and the British War Direction Machineries’, Revue internationale d'histoire militaire 47 (1980) pp.37–9.

Skodvin, ‘Norwegian neutrality’, p.128; Nils Ørvik, Decline of Neutrality (London: Frank Cass 1971) pp.227–8.

K. Assmann, The German Campaign in Norway (London: Naval Staff Admiralty 1948) p.19.

R. Knauss, ‘Der Feldzug in Norwegen 1940’,unpublished after-action narrative and analysis, n.d., p.18.

Ibid.; N. Naastad, ‘Norwegian Pre-War Threat Assessment and Air Power Doctrine’ (Paper for the annual Society for Military History conference, Montgomery AL, 1997) p.7. Intercepts from the German wireless interception station at Husum-Milstedt (Station W-22) in the pre-invasion period also reported a lack of military activity in Norway and Denmark, see USAFHSO K113.107–191 The Radio Intercept Service of the German Air Force. Colonel Kurt Gottschling, German Air Signal Corps (Retired). Berlin-Charlottenburg 1, p.143.

Kriegstagebuch der Seekriegsleitung, 1.Abteilung [hereafter KTB Skl] (Wilmington, DE: Scholarly Resources in cooperation with the US Naval Historical Center 1984) 9 March 1940.

D. Brown (ed.), Naval Operations of the Campaign in Norway, April–June 1940 (London and Portland, OR: Frank Cass 2000) pp.5–7; K. Assmann, ‘The German Invasion of Norway’, in M.L. Bartlett (ed.), Assault from the Sea: Essays on the History of Amphibious Warfare (Annapolis, MD: Naval Institute Press 1983) pp.242–3.

Assmann (note 18) pp.12–13.

Hubatsch (note 15) p.48.

A. Lee, The German Air Force (London: Duckworth 1946) p.50.

NA T971/20: Generalkommando X.Fl.K. Ia op Nr.10074/40 gKdos. Befehl für den Einsatz der 4./Fallsch.Jäg Regt.1 am Wesertag. Gefechtsstand, den 20.3.40.

NA T971/20: Abschrift. anlage 1 zu X.Fl.K.Ia Nr.10033/40 gKdos. Geheime Kommandosache! Feindnachrichtenblatt. Jutland.

NA T971/20: Anlage 3 zu Generalkommando des X.Fliegerk., Ia Br.B.Nr.10053/40 gKdos. Feindnachrichtenblatt Oslo und Oslofjord; see also NA T971/20: Anlage 4 zu Generalkommando des X.Fliegerkorps, Ia Br.B.Nr.10053/40 gKdos. Feindnachrichtenblatt Kristiansand, and NA T971/20 Anlage 6 zu X.Fl.K. Ia Nr.10053 gKdos. Feindnachrichtenblatt Bergen

NA T971/20: Anlage 3 zu Generalkommando des X.Fliegerk., Ia Br.B.Nr.10053/40 gKdos. Feindnachrichtenblatt Oslo und Oslofjord.

Numbering between 300 and 750 aircraft, a Fliegerkorps (air corps) was the largest operational command within an air fleet (Luftflotte). X Fliegerkorps was one of the Luftwaffe's strongest air corps with over 1,000 aircraft in total and was upgraded to a full air fleet, Luftflotte 5, within a week of the invasion. For an examination of the role of air power in Weserübung see: A. Claasen, Hitler's Northern War: The Luftwaffe's Ill-fated Campaign, 1940–1945 (Lawrence: Univ. Press of Kansas 2001).

KTB Skl, 28, 30, 31 March 1940.

Ibid., 30 March 1940; W. Gaul, ‘The Part Played by the German Air Force and the Naval Air Force in the Invasion of Norway’, in Essays by German Officers and Officials About World War II (Wilmington, DE: Scholarly Resources in cooperation with the US Naval Historical Center n.d.) pp.7–8.

A brief but useful chronological breakdown of events pertinent to aerial preparations and activities in the seven days prior to 9 April can be found in USAF Historical Research Agency, Maxwell Air Force Base, Montgomery AL [hereafter USAFHRA] K113:305: Kriegstagebuch der Gruppe XXI.

Gaul (note 32) pp.8–9.

Ibid.

USAFHRA K113.305: Kriegstagebuch der Gruppe XXI, 4 April 1940.

Ibid. 7 April 1940; S. Roskill, The War at Sea, Vol. 1 (London: HMSO 1954) p.158.

NA RG457/94–99: G.C. & C.S. Naval History, Vol. XXIII: Northern Waters, by Lt. Cdr L.A. Griffiths, RNVR, p.183.

Kahn (note 13) pp.215–17; USAFHRA K113.107–191: Colonel Kurt Gottschling, German Air Signal Corps (Retired), Radio Intercept Service of the German Air Force, p.143.

KTB Skl, 12 April 1940.

Ibid. 13 April 1940.

C. Shores, Fledgling Eagles: The Complete Account of Air Operations During the Phoney War and the Norwegian Campaign, 1940 (London: Grub Street 1991) p.217.

Quoted in N. Millar, War at Sea: A Naval History of World War II (London: Scribner 1995); J.L. Moulton, The Norwegian Campaign of 1940: A Study of Warfare in Three Dimensions (London: Eyre & Spottiswoode 1966) p.70.

Roskill (note 37) p.159.

Butler, Grand Strategy, Vol. II, September 1939–June 1941 (London: Cassell 1950) pp.122–3.

T.K. Derry, The Campaign in Norway (London: HMSO 1952) p.26.

Ibid.

R. Macleod (ed.), The Ironside Diaries, 1937–1940 (London: Constable 1962) pp.253, 257–8.

For an account of the woefully executed counter-landings in central Norway see: J. Adams, The Doomed Expedition: The Campaign in Norway 1940 (London: Leo Cooper 1989).

B. Stegemann, ‘Die Sicherung der europäischen Nordflanke: III. Das Unternehmen “Weserübung”’, in K.A. Maier et al. (eds), Das deutsche Reich und der Zweite Weltkrieg, Bd. 2, Die Errichtung der Hegemonie auf dem europäischen Kontinent (Stuttgart: Deutsche Verlags-Anstalt 1979) p.212; Hubatsch, ‘Weserübung’, (note 15) pp.65–7.

Shores (note 42) pp.224–5.

Ibid.

Roskill (note 37) p.164.

KTB Skl, 8 April 1940.

Moulton (note 43) p.72.

Olav Riste addresses the Norwegian failure to fully recognised the German threat in ‘A Complete Surprise: The German Invasion of Norway in 1940’, in International Commission of Military History ACTA No. 13 (Helsinki: International Commission of Military History 1991) pp.97–106. With regard to Norwegian intelligence post the invasion, see R. Ulstein, ‘Norwegian Intelligence in the Second World War’, in P. Salmon (ed.), Britain and Norway in the Second World War, (London: HMSO 1995) pp.129–39

KTB Skl, 3 April 1940.

For a narrative of the First and Second Battles of Narvik, see Derry (note 46) pp.43–6, 48–52.

Moulton (note 43) p.93.

NA RG457/94–99: G.C. & C.S. Air and Military History, Vol. II: The War in the West, 1940–1941, by Wing Commander P. Calvocoressi et al., p.15. As the general prefare to the air and military component points out, the object of the Government Code and Cipher School (GC&CS) histories was to ‘illustrate the contribution of Special Intelligence to Allied intelligence in the European Theatre of war’. Written between 1945 and early 1946, the volumes offer an insight into the quality and quantity of Ultra intelligence produced at Bletchley Park and made available to the intelligence staffs in the Allied commands. Other GC&CS material relevant to intelligence in Norway can be found in the twenty-third volume of the naval series: NA RG457/94–99: G.C. & C.S. Naval History, Volume XXIII: Northern Waters, by Lt. Cdr. L.A. Griffiths, RNVR.

R. Lewin, Ultra Goes to War: The Secret Story (London: Hutchinson 1978) p.61.

R. Bennett, Behind the Battle: Intelligence in the War with Germany, 1939–45 (London: Sinclair-Stevenson 1994) p.43. One of the best discussions of British intelligence and the invasion is provided by W.K. Wark, ‘Beyond Intelligence: The Study of British Strategy and the Norway Campaign, 1940’, in M.G. Fry (ed.), Power, Personalities and Policies: Essays in Honour of Donald Cameron Watt (London: Frank Cass 1993) pp.233–57.

NA RG457/94–99: G.C. & C.S. Air and Military History, Vol. II, p.14.

F.H. Hinsley et al., British Intelligence in the Second World War, Its Influence on Strategy and Operations, Vol. 1 (London: HMSO 1979) p.137.

NA RG457/94–99: G.C. & C.S. Air and Military History, Vol. II, (note 60) p.15.

Ibid.

Ibid.

Hinsley (note 64) p.140.

Bennett (note 59) p.41.

As a 20-old Bletchely Park cryptographer, Hinsley personally observed the difficulties associated with utilizing the material generated by Weserübung. See F.H. Hinsley, ‘BP, Admiralty, and naval Enigma’, in F.H. Hinsley and A. Stripp (eds), Code Breakers: The Inside Story of Bletchley Park (Oxford: OUP 1993) pp.77–8; also S. Budiansky, Battle of Wits: The Complete Story of Codebreaking in World War II (London, Penguin 2000) pp.146–8.

Ibid., p.43.

Shores (note 42) p.277; M. Middlebrook and C. Everitt, The Bomber Command War Diaries: An Operational Reference Book, 1939–1945 (NY: Viking 1985) p.35.

Hinsley (note 64) p.140.

Additional information

Notes on contributors

Adam Claasen

Adam Claasen is a Lecturer in Modern History, International Relations and Politics at Massey University, Auckland, New Zealand. As well as teaching papers on politics, international relations, and German history, he also lectures on the Russo-Chechen Wars and the Arab–Israeli conflict. His most recent publication is Hitler's Northern War: The Luftwaffe's Ill-fated Campaign, 1940–45 (Lawrence: University Press of Kansas 2001), in which he examines the role of German airpower in Norway from the 1940 invasion until the war's end.