1 For example, Michael E. Brown, Sean M. Lynn-Jones and Steven E. Miller (eds), Debating the Democratic Peace (Cambridge Mass and London: MIT Press, 1996); Steve Chan, ‘In Search of Democratic Peace: Problems and Promise’, Mershon International Studies Review, 41 (1997), pp. 56–91; Charles Lipson, Reliable Partners. How Democracies have made a Separate Peace (Princeton and Oxford: Princeton University Press, 2003); Karen Rasler, William R. Thompson, Puzzles of the Democratic Peace Theory, Geopolitics and the Transformation of World Politics (Basingstoke: Palgrave Macmillan, 2005).

2 For trenchant criticism of the static definitions over time of democracy, war and the state in much of the literature, see Tarak Barkawi and Mark Laffey (eds), Democracy, Liberalism and War. Rethinking the Democratic Peace Debate (Boulder and London: Rienner, 2001), pp. 1–23.

3 Joseph S. Nye, Understanding International Conflicts. An Introduction to Theory and History (6th edition, New York et al.: Pearson Longman, 2007), p. 49.

4 For an important collection of ‘hard’ case studies of this kind, see Miriam Fendius Elman (ed.), Paths to Peace. Is Democracy the Answer? (Cambridge, Mass. and London: MIT Press, 1997).

5 For a quantitative argument that there has been a learning process allowing democratic peace norms to become increasingly effective over time, see Lars-Erik Cederman, ‘Back to Kant: Reinterpreting the Democratic Peace as a Macrohistorical Learning Process’, American Political Science Review, 95 (2001), pp. 15–31.

6 On this controversy see Ido Oren, ‘The Subjectivity of the “Democratic Peace”: Changing US Perceptions of Imperial Germany’, International Security, 20 (1995), pp. 147–84. He makes the important points that the definition of democracy has changed over time, the perception of Imperial Germany as not a democracy was in part a product of the First World War and since the 1980s the whole idea that Germany followed a separate path of development from an assumed standard model of France, Britain and the US has been shown to be simplistic. On the last, see David Blackbourn and Geoff Eley, The Peculiarities of German History. Bourgeois Society and Politics in Nineteenth-Century Germany (Oxford: Oxford University Press, 1984). On the other hand, it remains the case that although from 1871 at national level Germany had a democratic (male) franchise; it did not have a democratic government. Ministers were appointed by the Crown and not responsible to the Reichstag, and, in addition, the Social Democrats – the largest single party after 1912 – were excluded from power. For a recent reassessment of the ‘special path’ question, see, Heinrich August Winkler, Germany. The Long Road to the West, 2 vols. (Engl. edition, Oxford: Oxford University Press, 2006, 2007).

7 The analysis could be extended to relations between France and the German Federal Republic since the Second World War but the contrasts with the earlier period are more evident than the similarities. The German Federal Republic was also committed to work for change in the international system – German reunification – but the distribution of power after 1945 ruled out a military option. In addition the development of international institutions and the Federal Republic's incorporation into them – notably NATO and the European Community – gave the FRG a stable role within a Western alliance system and in turn assisted the consolidation of German democracy. After the experience of Nazism and the Second World War, that was in any case dominated by democratic parties committed to the peaceful settlement of disputes to a far greater extent than during the Weimar Republic.

8 On the problem of democratising states, see Edward D. Mansfield and Jack Snyder, ‘Democratization and the Danger of War’, in Brown et al. (eds), Debating the Democratic Peace, pp. 301–34 and Jack Snyder, From Voting to Violence. Democratization and Nationalist Conflict (New York and London: Norton, 2000). On the constituents of a consolidated democracy, see Juan J. Linz and Alfred Stepan, Problems of Democratic Transition and Consolidation (Baltimore and London: Johns Hopkins University Press, 1996).

9 On the importance of parties and leaders, see Elman (ed.), Paths to Peace, pp. 483–5.

10 As already noted by Christopher Layne in his discussion of ‘near misses’, ‘Kant or Cant: The Myth of the Democratic Peace’, in Brown et al. (eds), Debating the Democratic Peace, pp. 185–90. The Ruhr occupation is included in the category of Militarised Interstate Disputes in the Correlates of War Project, version 3.02; for details of this data set, see Faten Ghosn, Glenn Palmer and Stuart A. Bremer, ‘The MID3 Data Set, 1993–2001: Procedures, Coding, Rules, and Description’, Conflict Management and Peace Science, 21 (2004), pp. 133–54. There is a detailed study of French policy in Stanislas Jeannesson, Poincaré, la France et la Ruhr (1922–1924) (Strasbourg: Presse Universitaires de Strasbourg, 1998) and of the effect on Germany in Conan Fischer, The Ruhr Crisis 1923–1924 (Oxford: Oxford University Press, 2003).

11 Arnold J. Toynbee, Survey of International Affairs 1924 (London: Oxford University Press, 1928), p. 279. Perhaps because of the definitions used there, the occupation is recorded as ending on 11 July 1923 and causing zero fatalities in the Correlates of War Project data set (see preceding footnote). In fact it continued until July 1925 though economic control of the area was restored to Germany in October 1924.

12 F. L. Carsten, The Reichswehr and Politics 1918–1933 (Oxford: Clarendon Press, 1966), pp. 147–63.

13 This example tends to confirm the quantitative argument that ‘power preponderance’ on one side to a dispute (in this case France) does not lead to a lower likelihood of a negotiated outcome. If, as in this example, victory is not a viable result because of democratic norms, then military power alone will not be decisive. For the quantitative analysis, see William J. Dixon and Paul D. Senese, ‘Democracy, Disputes, and Negotiated Settlements’, Journal of Conflict Resolution, 46 (2002), pp. 560–61.

14 Elspeth Y. O'Riordan, Britain and the Ruhr Crisis (Basingstoke: Palgrave, 2001); Patrick O. Cohrs, The Unfinished Peace after World War I. America, Britain and the Stabilisation of Europe 1919–1932 (Cambridge University Press: Cambridge, 2006), pp. 100–15.

15 Despite the literature on the association of peace and commerce between democracies deriving from Kant, the relationship between different forms of capitalism and democracy is an under-researched aspect of democratic peace theory. The most powerful intellectual advocate of the need to restore the German economy in the interests of peace was J. M. Keynes in The Economic Consequences of the Peace (London: Macmillan, 1st edition, 1919, annotated edition, 1971). On the role of the Dawes Plan in stabilising the Weimar Republic by giving organised interests a stake in it through the loans, see Charles Maier, Recasting Bourgeois Europe. Stabilization in France, Germany and Italy in the Decade after World War I (Princeton: Princeton University Press, 1975), p. 481. Acquiring a stake in the Republic however did not necessarily mean internalising democratic values and after 1929, under the impact of the depression, some of the same organised interests helped to destabilise the Republic in favour of an authoritarian regime; Hans Mommsen, The Rise and Fall of Weimar Democracy (Engl. edition, Chapel Hill and London: The University of North Carolina Press, 1996), pp. 371–98.

16 Jon Jacobson, Locarno Diplomacy: German and the West 1925–1929 (Princeton: Princeton University Press, 1972).

17 Martin Walsdorff, Westorientierung und Ostpolitik. Stresemanns Rußlandpolitik in der Locarno Ära (Bremen: Schünemann, 1971), pp. 167–81.

18 Jonathan Wright, Gustav Stresemann. Weimar's Greatest Statesman (Oxford: Oxford University Press, 2002), p. 306.

19 Jon Jacobson, ‘Locarno, Britain and the Security of Europe’, in Gaynor Johnson (ed.), Locarno Revisited: European Diplomacy 1920–1929 (London and New York: Routledge, 2004), pp. 11–32.

20 Ibid., p. 16.

21 Jacobson, Locarno Diplomacy, p. 29; Richard S. Grayson, Austen Chamberlain and the Commitment to Europe. British Foreign Policy 1924–29 (London: Cass, 1997), pp. 125–7.

22 Cohrs, The Unfinished Peace, pp. 247–52.

23 Alan Cassels, ‘Locarno: Early Test of Fascist Intentions’, in Johnson (ed.), Locarno Revisited, pp. 80–94.

24 Peter Krüger, ‘Locarno und die Frage eines europäischen Sicherheitssystems unter besonderer Berücksichtigung Ostmitteleuropas’, in Ralph Schattkowsky (ed.), Locarno und Osteuropa. Fragen eines europäischen Sicherheitssystems in den 20er Jahren (Marburg: Hitzeroth, 1994), pp. 9–27.

25 On the problem of distinguishing norms from interests see Henry S. Farber and Joanne Gowa, ‘Polities and Peace’, in Brown et al. (eds), Debating the Democratic Peace, pp. 241–2. Their argument that interests provide the better explanation is more persuasive for the bipolar system of the Cold War (pp. 261–2) where the interests of democratic states were more clearly aligned together against the Soviet Union than was the case in the more diffuse international environment of the 1920s. In the latter, the divisions ran between status quo and revisionist states (whether democratic or non-democratic) as well as between the Soviet Union and the capitalist states and in addition, the refusal of the US to accept commitments to European security created further uncertainty. In such conditions where different alignments of interest were possible, it is not so easy to discount the role of norms in shaping the way interests were perceived.

26 Andreas Hasenclever and Brigitte Weiffen, ‘International institutions are the key: a new perspective on the democratic peace’, Review of International Studies, 32 (2006), pp. 563–85. Their example of the way in which NATO has affected Franco-German relations is particularly relevant; ibid. pp. 578–80.

27 In this they conformed to the analysis in John Mueller, Retreat from Doomsday. The Obsolescence of Major War (Rochester, New York: University of Rochester Press, 1996), pp. 56–62.

28 Jacques Bariéty, ‘Aristide Briand: les raisons d'un oubli’, in Antoine Fleury (ed.), Le Plan Briand d'Union fédérale européenne (Bern: Lang, 1998), pp. 5–6.

29 League of Nations Official Journal, Special Supplement no. 44: Records of the Seventh Ordinary Session of the Assembly (Geneva, 1926), pp. 51–52.

30 From his introduction to an appreciation of the Weimar Republic's first ten years, Zehn Jahre Deutsche Geschichte 1918–1928 (Berlin: Stollberg, [1928]), p. viii.

31 Wright, Stresemann, p. 417.

32 Austen Chamberlain, Down the Years (4th edition, Edinburgh: Edinburgh Press, 1935), p. 188.

33 Stresemann to Crown Prince Wilhelm, 7 September 1925; quoted in Wright, Stresemann, pp. 326–7.

34 Ibid., 323.

35 Ibid., 334.

36 Stephanie Salzmann, Great Britain, Germany and the Soviet Union. Rapallo and After, 1922–1934 (Woodbridge: The Boydell Press, 2003), p. 86.

37 Matthias Schulz, Deutschland, der Völkerbund und die Frage der europäischen Wirtschaftsordnung 1925–1933 (Hamburg: Krämer, 1997), pp. 45–173.

38 Peter Krüger, Die Aussenpolitik der Republik von Weimar (Darmstadt: Wissenschaftliche Buchgesellschaft, 1985), pp. 368–72.

39 Clemens August Wurm, ‘Internationale Kartelle und die deutsch-französischen Beziehungen 1924–1930: Politik, Wirtschaft, Sicherheit’, in Stephen A. Schuker (ed.), Deutschland und Frankreich. Vom Konflikt zur Aussöhnung (Munich: Oldenbourg, 2000), pp. 97–115.

40 Jonathan Wright and Julian Wright, ‘One mind at Locarno? Aristide Briand and Gustav Stresemann’, in Steven Casey and Jonathan Wright (eds), Mental Maps of the Era of Two World Wars (Basingstoke: Palgrave Macmillan, 2008).

41 C. A. Macartney, Survey of International Affairs 1925, vol. 2 (London: Oxford University Press, 1928), p. 56.

42 Wright, Stresemann, p. 339.

43 Christoph M. Kimmich, Germany and the League of Nations (Chicago and London: The University of Chicago Press, 1976), pp. 81–4.

44 Wright, Stresemann, pp. 396, 480–2.

45 François Seydoux, Beiderseits des Rheins. Erinnerungen eines französischen Diplomaten (Frankfurt am Main: Societäts Verlag, 1975), p. 38.

46 On the similarities between the policies pursued by Briand and Poincaré, see John Keiger, ‘Poincaré, Briand and Locarno: Continuity in French Diplomacy in the 1920s’, in Johnson (ed.), Locarno Revisited, pp. 95–107.

47 Wright, Stresemann, p. 412.

48 Ibid., pp. 415–6.

49 Franz Knipping, Deutschland, Frankreich und das Ende der Locarno-Ära 1928–1931 (Munich: Oldenbourg, 1987).

50 Rolf Ahmann, ‘Sicherheitsprobleme Ostmitteleuropas nach Locarno 1926 bis 1936’, in Schattkowsky (ed.), Locarno und Osteuropa, pp. 183–200.

51 Michael Geyer, Aufrüstung oder Sicherheit. Die Reichswehr in der Krise der Machtpolitik 1924–1936 (Wiesbaden: Franz Steiner, 1980), pp. 191–217.

52 For a quantitative study of the beneficial effects by contrast of preferential trading areas in promoting peace between 1950 and 1985, see Edward D. Mansfield and Jon C. Pevehouse, ‘Trade Blocs, Trade Flows, and International Conflict’, International Organization, 54 (2000), pp. 775–808.

53 Wright, Stresemann, p. 265.

54 Wurm, ‘Internationale Kartelle’, pp. 105–15.

55 Fleury, Le Plan Briand; Wright, Stresemann, 483–486.

56 Wurm, ‘Internationale Kartelle’, pp. 102–3.

57 Cohrs, The Unfinished Peace, pp. 378–408.

58 Snyder, From Voting to Violence, pp. 117–28.

59 ‘Democratization and the Danger of War’, p. 303.

60 Heinrich August Winkler, Der Schein der Normalität. Arbeiter und Arbeiterbewegung in der Weimarer Republik 1924 bis 1930 (2nd edition, Berlin and Bonn: J. H. W. Dietz Verlag, 1988), p. 250.

61 Wright, Stresemann, p. 435.

62 Ibid., pp. 369, 441, 487–9.

63 For a quantitative study of the linkage between democratisation and dispute escalation based on the Militarised Interstate Disputes data, see Paul D. Senese, ‘Democracy and Maturity: Deciphering Conditional Effects on Levels of Dispute Intensity’, International Studies Quarterly, 43 (1999), pp. 483–502. Interestingly, he finds that the effect of democracy ‘is pacifying (and relatively greater in magnitude) among the population of disputes fought between less mature foes, compared to its aggravating effect among the population of disputes fought between more mature antagonists.’ Ibid., p. 500.

64 Knipping, Deutschland, Frankreich und das Ende der Locarno-Ära, pp. 84–9; Andreas Rödder, Stresemanns Erbe: Julius Curtius und die deutsche Außenpolitik 1929–1931 (Paderborn: Schöningh, 1996), pp. 113–9, 186–222.

65 Wilhelm Deist, The Wehrmacht and German Rearmament (Basingstoke: Macmillan, 1981), pp. 12–16.

66 For examples of public opinion as a force for war, see Elman, Paths to Peace, pp. 487–8.

67 Lipson, Reliable Partners, p. 4.

68 There is a detailed account in James Thomas Emmerson, The Rhineland Crisis 7 March 1936. A Study in Mulilateral Diplomacy (London: Temple Smith, 1977).

69 Martin S. Alexander, The Republic in danger. General Maurice Gamelin and the politics of French defence, 1933–1940 (Cambridge: Cambridge University Press, 1992), pp. 180–1.

70 The Earl of Avon, The Eden Memoirs. Facing the Dictators (London: Cassell, 1962), p. 346.

71 Philip Towle, ‘Taming or Demonising an Aggressor: The British Debate on the End of Locarno’, in Johnson (ed.), Locarno Revisited, pp. 178–98.

72 David Owen Kieft, Belgium's Return to Neutrality (Oxford: Clarendon Press, 1972).

73 Jonathan Wright, Germany and the Origins of the Second World War (Basingstoke: Palgrave Macmillan, 2007), pp. 70–2.

74 As argued by William R. Thompson, ‘Democracy and Peace: Putting the Cart before the Horse?’, International Organization, 50 (1996), pp. 141–74. His example of the influence of external factors, notably the depression, in reversing the process of democratisation in Taisho Japan (ibid. pp. 164–70) offers obvious comparisons with Weimar Germany.

75 The Third Republic also had its weaknesses including executive instability but the strength of the French Republican tradition gave democracy a safety net (until military defeat in 1940) which was lacking in the Weimar Republic. For comparative studies of the two democracies see Horst Möller and Manfred Kittel (eds), Demokratie in Deutschland und Frankreich 1918–1933/40 (Munich: Oldenbourg, 2002) and Thomas Raithel, Das schwierige Spiel des Parlamentarismus. Deutscher Reichstag und französische Chambre des Députés in den Inflationskrisen der 1920er Jahre (Munich: Oldenbourg, 2005).

76 Wolfram Wette, ‘Ideology, Propaganda, and Internal Politics as Preconditions of the War Policy of the Third Reich’, in Wilhelm Deist, Manfred Messerschmidt, Hans-Erich Volkmann and Wolfram Wette, Germany and the Second World War, vol. 1, The Build-up of German Aggression (Engl. edition, Oxford: Clarendon Press, 1990), pp. 96–118.