¹ Chan, Steve, ‘Mirror, mirror on the wall … are the freer countries more Pacific?’, Journal of Conflict Resolution, 28:4 (1984), pp. 617–648 Google Scholar; Dixon, William J., ‘Democracy and the peaceful settlement of international conflict’, American Political Science Review, 88:1 (1994), pp. 14–32 Google Scholar; Maoz, Zeev and Abdolali, Nasrin, ‘Regime types and international conflict’, Journal of Conflict Resolution, 33:1 (1989), pp. 3–35 CrossRefGoogle Scholar; Ray, James Lee, ‘Friends as foes: International conflict and wars between formal allies’, in Charles S. Gochman and Alan Ned Sabrosky (eds), Prisoners of War? (Lexington, MA: Lexington Book, 1990), pp. 73–91 Google Scholar; Russett, Bruce, Controlling the Sword: The Democratic Governance of National Security (Cambridge, MA: Harvard University Press, 1990)Google Scholar; Russett, Bruce, ‘The democratic peace: “and yet it moves”’, International Security, 19:4 (1995), pp. 164–175 Google Scholar.

² de Mesquita, Bruce Bueno, Morrow, James D., Siverson, Randolph M., and Smith, Alastair, ‘An institutional explanation of the democratic peace’, American Political Science Review, 93:4 (1999), pp. 791–807 Google Scholar; Maoz, Zeev and Russett, Bruce, ‘Normative and structural causes of democratic peace, 1946–1986’, American Political Science Review, 87:3 (1993), pp. 624–638 Google Scholar; Morgan, Clifton T. and Campbell, Sally H., ‘Domestic structures, decisional constraints, and war: So why do Kant democracies fight?’, Journal of Conflict Resolution, 35:2 (1991), pp. 187–211 Google Scholar; Reiter, Dan and Stam, Allan C., Democracies at War (Princeton, NJ: Princeton University Press, 2002)Google Scholar; Russett, Bruce, Grasping the Democratic Peace: Principles for a Post-Cold War World (Princeton, NJ: Princeton University Press, 1993)Google Scholar; Siverson, Randolph, ‘Democracies and war participation: In defence of the institutional constraints argument’, European Journal of International Relations, 1:4 (1995), pp. 481–489 CrossRefGoogle Scholar.

³ Dixon, ‘Democracy and the peaceful settlement on international conflict’; Doyle, Michael W., ‘Liberalism and world politics’, American Political Science Review, 80:4 (1986), pp. 1151–1169 CrossRefGoogle Scholar; Maoz and Russett, ‘Normative and structural causes of democratic peace’; Raymond, Gregory A., ‘Democracies, disputes, and third-party intermediaries’, Journal of Conflict Resolution, 38:1, pp. 24–42 (1994)Google Scholar; Risse-Kappen, Thomas, ‘Democratic peace – warlike democracies?: a social constructivist interpretation of the liberal argument’, European Journal of International Relations, 1:4 (1995), pp. 491–517 Google Scholar; Russett, ‘Grasping the democratic peace’; Weart, Spencer R., Never at War: Why Democracies Will Not fight One Another (New Haven, CT: Yale University Press, 1998)Google Scholar.

⁴ Chilton, Adam S., ‘The laws of war and public opinion: an experimental study’, Journal of Institutional and Theoretical Economics, 171:1 (2015), pp. 181–201 Google Scholar; Geva, Nehemia and Hanson, D. Christopher, ‘Cultural similarity, foreign policy actions, and regime perception: an experimental study’, Political Psychology, 20:4 (1999), pp. 803–827 Google Scholar; Johns, Robert and Davies, Graeme A. M., ‘Democratic peace or clash of civilizations? Target states and support for war in Britain and the United States’, Journal of Politics, 74:4 (2012), pp. 1038–1052 CrossRefGoogle Scholar; Mintz, Alex and Geva, Nehemia, ‘Why don’t democracies fight each other?: an experimental study’, Journal of Conflict Resolution, 37:3 (1993), pp. 484–503 CrossRefGoogle Scholar; Tomz, Michael and Weeks, Jessica L., ‘Public opinion and the democratic peace’, American Journal of Political Science, 107:4 (2013), pp. 849–865 Google Scholar.

⁵ Kant, Immanuel, Principles of Politics and Perpetual Peace, trans. W. Hastie (Boston, MA: Digireads, 2010)Google Scholar.

⁶ Democratic peace is usually viewed as a key constituent element of liberal peace or Kantian peace, which highlights Kant’s emphasis of the peace-bolstering role played by ‘republics’ (democracies) as well as by interstate trade and international organisation. For a comprehensive elaboration of the Kantian peace triangle, see Russett, Bruce and Oneal, John, Triangulating Peace: Democracy, Interdependence, and International Organizations (New York: W. W. Norton & Co., 2001)Google Scholar.

⁷ Doyle, Michael W., ‘Kant, liberal legacies, and foreign affairs’, Philosophy & Public Affairs, 12:3 (1983), pp. 205–235 Google Scholar; Doyle, ‘Liberalism and world politics’.

⁸ Babst, Dean V., ‘Elective governments – a force for peace’, Wisconsin Sociologist, 3:1 (1964), pp. 9–14 Google Scholar.

⁹ For recent reviews of the literature, see Geis, Anna and Wagner, Wolfgang, ‘How far is it from Königsberg to Kandahar? Democratic peace and democratic violence in international relations’, Review of International Studies, 37:4 (2011), pp. 1555–1577 Google Scholar; Hayes, Jarrod, ‘The democratic peace and the new evolution of an old idea’, European Journal of International Relations, 18:4 (2012), pp. 767–791 CrossRefGoogle Scholar; Hegre, Håvard, ‘Democracy and armed conflict’, Journal of Peace Research, 51:2 (2014), pp. 159–172 CrossRefGoogle Scholar.

¹⁰ Kinsella, David, ‘No rest for the democratic peace’, American Political Science Review, 99:3 (2005), p. 453 Google Scholar.

¹¹ Boehmer, Charles R., ‘A reassessment of democratic pacifism at the monadic level of analysis’, Conflict Management and Peace Science, 25:1 (2008), pp. 81–94 Google Scholar; Quackenbush, Stephen L. and Rudy, Michael, ‘Evaluating the monadic democratic peace’, Conflict Management and Peace Science, 26:3 (2009), pp. 268–285 Google Scholar; Small, Melvin and Singer, J. David, ‘The war-proneness of democratic regimes’, Jerusalem Journal of International Relations, 1:4 (1976), pp. 50–69 Google Scholar. For a recent review of the monadic democratic peace literature, see Dieterich, Sandra, Hummel, Hartwig, and Marschall, Stefan, ‘Bringing democracy back in: the democratic peace, parliamentary war powers and European participation in the 2003 Iraq War’, Cooperation and Conflict, 50:1 (2015), pp. 89–91 Google Scholar. For empirical studies citing support for monadic democratic peace, see, for example, Bremer, Stuart A., ‘Dangerous dyads: Conditions affecting the likelihood of interstate war, 1816–1965’, Journal of Conflict Resolution, 36:2 (1992), pp. 309–341 Google Scholar; DeRouen, Karl R. Jr and Goldfinch, Shaun, ‘Putting the numbers to work: Implications for violence prevention’, Journal of Peace Research, 42:1 (2005), pp. 27–45 Google Scholar; Huth, Paul K. and Allee, Todd L., The Democratic Peace and Territorial Conflict in the Twentieth Century (New York: Cambridge University Press, 2002)Google Scholar; Rummell, Rudolph J., ‘Democracies ARE less warlike than other regimes’, European Journal of International Relations, 1:4 (1995), pp. 457–479 CrossRefGoogle Scholar.

¹² Dixon, ‘Democracy and the peaceful settlement of international conflict’; Doyle, ‘Liberalism and world politics’; Doyle, Michael W., ‘Three pillars of the liberal peace’, American Political Science Review, 99:3 (2005), pp. 463–466 Google Scholar; Maoz and Russett, ‘Normative and structural causes of democratic peace’; Russett, ‘Grasping the democratic peace’; Weart, ‘Never at war’.

¹³ Dixon, ‘Democracy and the peaceful settlement of international conflict’; Maoz and Russett, ‘Normative and structural causes of democratic peace’; Russett, ‘Grasping the democratic peace’.

¹⁴ Maoz and Russett, ‘Normative and structural causes of democratic peace’; Russett, ‘Grasping the democratic peace’.

¹⁵ Doyle, ‘Liberalism and world politics’; Doyle, ‘Three pillars of the liberal peace’; Owen, John M., ‘How liberalism produces democratic peace’, International Security, 19:2 (1994), pp. 87–125 Google Scholar.

¹⁶ Doyle, ‘Liberalism and world politics’, p. 1152.

¹⁷ In terms of outcomes, the third possible option – a like dyad consisting of two non-democracies – basically yields the same expectations as an unlike dyad.

¹⁸ Maoz and Russett, ‘Normative and structural causes of democratic peace’, p. 625; Risse-Kappen, ‘Democratic peace – warlike democracies?’

¹⁹ Ember, Carol R., Ember, Melvin, and Russett, Bruce, ‘Peace between participatory polities: a cross-cultural test of the “democracies rarely fight each other” hypothesis’, World Politics, 44:4 (1992), pp. 573–599 Google Scholar.

²⁰ Bueno de Mesquita et al., ‘An institutional explanation of the democratic peace’; Maoz and Russett, ‘Normative and structural causes of democratic peace’; Morgan and Campbell, ‘So why Kant democracies fight?’; Reiter and Stam, Democracies at War; Russett, ‘Grasping the democratic peace’; Siverson, ‘Democracies and war participation’.

²¹ Elman, Miriam F., ‘The need for a qualitative test of the democratic peace theory’, in Miriam F. Elman (ed.), Paths to Peace: Is Democracy the Answer? (Cambridge, MA: MIT Press, 1997), p. 13 Google Scholar.

²² Kant, Perpetual Peace, p. 57.

²³ Doyle, , ‘Three pillars of the liberal peace’, pp. 464–465 Google Scholar.

²⁴ Boehmer, ‘A reassessment of democratic pacifism’; Quackenbush and Rudy, ‘Evaluating the monadic democratic peace’.

²⁵ Lake, David A., ‘Powerful pacifists: Democratic states and war’, American Political Science Review, 86:1 (1992), pp. 24–37 Google Scholar; see also de Mesquita, Bruce Bueno and Siverson, Randolph M., ‘Nasty or nice? Political systems, endogenous norms, and the treatment of adversaries’, Journal of Conflict Resolution, 41:1 (1997), pp. 175–199 Google Scholar; Bueno de Mesquita et al., ‘An institutional explanation of the democratic peace’; Gelpi, Cristopher F. and Griesdorf, Michael, ‘Winners or losers? Democracies in international crisis, 1918–94’, American Political Science Review, 95:3 (2001), pp. 633–647 Google Scholar; Reiter and Stam, Democracies at War; Siverson, ‘Democracies and war participation’.

²⁶ Eichenberg, Richard C., ‘Victory has many friends: US public opinion and the use of military force, 1981–2005’, International Security, 30:1 (2005), pp. 140–177 Google Scholar; Eichenberg, Richard C., ‘Citizen opinion on foreign policy and world politics’, in Russell J. Dalton and Hans-Dieter Klingemann (eds), The Oxford Handbook of Political Behavior (Oxford: Oxford University Press, 2007), pp. 383–400 Google Scholar; Feaver, Peter D. and Gelpi, Christopher, Choosing Your Battles: American Civil-Military Relations and the Use of Force (Princeton, NJ: Princeton University Press, 2004)Google Scholar; Gelpi, Christopher, Feaver, Peter D., and Reifler, Jason, ‘Success matters: Casualty sensitivity and the war in Iraq’, International Security, 30:3 (2005–6), pp. 7–46 Google Scholar.

²⁷ Johns and Davies, ‘Democratic peace or clash of civilizations?’; Tomz and Weeks, ‘Public opinion and the democratic peace’; see also Chilton, ‘The laws of war and public opinion’; Geva and Hanson, ‘Cultural similarity, foreign policy action, and regime perceptions’; Mintz and Geva, ‘Why don’t democracies fight each other?’.

²⁸ Farber, Henry S. and Gowa, Joanne, ‘Polities and peace’, International Security, 20:2 (1995), pp. 123–146 Google Scholar; Gates, Scott, Knutsen, Torbjørn L., and Moses, Jonathon W., ‘Democracy and peace: a more skeptical view’, Journal of Peace Research, 33:1 (1996), pp. 1–10 CrossRefGoogle Scholar; Layne, Christopher, ‘Kant or Cant: the myth of the democratic peace’, International Security, 19:2 (1994), p. 40 Google Scholar; Rosato, Sebastian, ‘The flawed logic of the democratic peace theory’, American Political Science Review, 97:4 (2003), pp. 585–602 Google Scholar; Spiro, David, ‘The insignificance of the liberal peace’, International Security, 19:2 (1994), pp. 50–86 Google Scholar; Waltz, Kenneth N., ‘Structural realism after the Cold War’, International Security, 25:1 (2000), pp. 5–41 CrossRefGoogle Scholar. For well-argued rebuttals of this criticism, see Doyle, ‘Three pillars of the liberal peace’; Kinsella, ‘No rest for the democratic peace’.

²⁹ Gartzke, Erik, ‘The capitalist peace’, American Journal of Political Science, 51:1 (2007), pp. 166–191 Google Scholar; Mousseau, Michael, ‘The democratic peace unraveled: it’s the economy’, International Studies Quarterly, 57:1 (2013), pp. 186–197 CrossRefGoogle Scholar; Mousseau, Michael, Hegre, Håvard, and Oneal, John R., ‘How the wealth of nations conditions the liberal peace’, European Journal of International Relations, 9:2 (2003), pp. 277–314 Google Scholar.

³⁰ Layne, ‘The myth of the democratic peace’.

³¹ Gilpin, Robert, War and Change in World Politics (Cambridge: Cambridge University Press, 1981)Google Scholar; Wohlforth, William C., ‘The stability of a unipolar world’, International Security, 24:1 (1999), pp. 5–41 Google Scholar.

³² Miller, Paul D., ‘American grand strategy and the democratic peace’, Survival, 54:2 (2012), pp. 49–76 Google Scholar; Rock, Stephen R. ‘Anglo–US relations, 1845–1930: Did shared liberal values and democratic institutions keep the peace?’, in Miriam F. Elman (ed.), Paths to Peace: Is Democracy the Answer (Cambridge, MA: MIT Press, 1997), pp. 101–149 Google Scholar; Rosato, ‘The flawed logic of the democratic peace theory’, pp. 599–600. For a counter-argument to Rosato’s ‘imperialist peace’ claim, see Kinsella, ‘No rest for the democratic peace’.

³³ Data and Do-file can be obtained by request from the corresponding author.

³⁴ Bryk, Anthony S. and Raudenbusch, Stephen W., Hierarchical Linear Models: Applications and Data Analysis Methods (Newbury Park, CA: Sage)Google Scholar; Hox, Joop, Multilevel Analysis: Techniques and Applications (New York: Routledge, 2010)Google Scholar.

³⁵ Steenbergen, Marci R. and Jones, Bradford S., ‘Modeling multilevel data structures’, American Journal of Political Science, 46:1 (2002), pp. 551–569 Google Scholar.

³⁶ As our main concern is with the coefficient estimates, and since we are running large and complex models, we use the Laplacian approximation to calculate our models. Laplace approximation is equivalent to modelling curvature adaptive Gaussian quadrature with one integration point.

³⁷ The regressions were run in Stata (version 13), employing a random intercept model.

³⁸ For a further elaboration of the WVS methodology and sampling procedures, see World Values Survey’s home page, available at: {http://www.worldvaluessurvey.org/}. The datasets are made available through the Norwegian Social Science Data Services (NSD). Neither Ronald Inglehart, WVS, or NSD are responsible for the analysis or interpretations made in this article.

³⁹ Inglehart, Ronald F., Puranen, Bi, and Welzel, Christian, ‘Declining willingness to fight for one’s country: the individual-level basis of the long peace’, Journal of Peace Research, 52:4 (2015), pp. 418–434 Google Scholar.

⁴⁰ A sixth WVS wave was released at the time of writing.

⁴¹ Despite that there are five WVS waves, the number of units at Level 2 is only slightly double that of Level 3. This is primarily due to variations in the number of countries surveyed in each wave. In addition, some of the survey questions that form the basis of our individual-level data are not included for certain country-years.

⁴² On the basis of a so-called empty model, we estimated the share of variance attributable to each of the three levels. Level 1 accounts for 86.8 per cent; Level 2=3.5 per cent; and Level 3=9.7 per cent. The relatively low share attributable to Level 2 likely obtains because country-specific characteristics usually change only slowly over time; Level 3 presumably captures a substantial portion of this variance.

⁴³ Achen, Christopher H., ‘Let’s put garbage-can regressions and garbage-can probits where they belong’, Conflict Management and Peace Science, 22:4 (2005), pp. 327–339 Google Scholar; Clarke, Kevin A., ‘The phantom menace: Omitted variable bias in econometric research’, Conflict Management and Peace Science, 22:4 (2005), pp. 341–352 Google Scholar; Ray, James Lee, ‘Constructing multivariate analyses (of dangerous dyads)’, Conflict Management and Peace Science, 22:4 (2005), pp. 277–292 Google Scholar.

⁴⁴ Oneal, John R. and Russett, Bruce, ‘Rule of three, let it be? When more really is better’, Conflict Management and Peace Science, 22:4 (2005), pp. 293–310 Google Scholar.

⁴⁵ Of course, this strategy also lessens any concerns about multicollinearity, which tolerance tests, in any case, show is not an issue (with the partial exception for those models which include interaction variables, where tolerance values range between 0.16 and 0.28; that is, at levels that are generally considered just acceptable). For example, correlations between the six individual-level variables are generally fairly low; the highest – 0.23 – is between Trust in military and National pride. Tolerance level for all non-interaction variables are above 0.70.

⁴⁶ Gibson, Stephen and Noret, Nathalie, ‘Historical experiences, collective memory, and willingness to fight for one’s country: Comments on Paez et al.’, Journal of Cross-Cultural Psychology, 41:3 (2010), pp. 445–450 Google Scholar.

⁴⁷ Indeed, snapshots of scores on the dependent variable do suggest that there are mechanisms present that cannot be explained by any systematic bias in the data. For example, national scores on Bellicosity for three of the liberal-democratic Nordic countries – Norway, Sweden and Finland – are quite high (always above 0.83). This is likely due to their proximity to Russia/USSR or, relatedly, to the existence of military conscription. We account for such mechanisms in the empirical analysis.

⁴⁸ Herrmann, Richard K., Isernia, Pierangelo, and Segatti, Paolo, ‘Attachment to the nation and International Relations: Dimensions of identity and their relationship to war and peace’, Political Psychology, 30:5 (2009), pp. 721–754 Google Scholar; Kosterman, Rick and Feshbach, Seymour, ‘Toward a measure of patriotic and nationalistic attitudes’, Political Psychology, 10:2 (1989), pp. 257–274 Google Scholar.

⁴⁹ Herrmann, Isernia, and Segatti, ‘Attachment to the nation and International Relations’, p. 723.

⁵⁰ The question posed to respondents is: How proud are you to be an [name of country]? (1) Very proud; (2) Quite proud; (3) Not very proud; (4) Not at all proud. We recoded the variable prior to the statistical analysis so that high values reflect high national pride.

⁵¹ Marshall, Monty G., Gurr, Ted Robert, and Jaggers, Keith, ‘Polity IV Project: Political Regime Characteristics and Transitions, 1800–2009. Dataset Users’ Manual’ (Vienna, VA: Center for Systemic Peace, 2010)Google Scholar. See also {http://www.systemicpeace.org/polity/polity4.htm}.

⁵² Epstein, David L., Bates, Robert, Goldstone, Jack, Kristensen, Ida, and O’Halloran, Sharyn, ‘Democratic transitions’, American Journal of Political Science, 50:3 (2006), pp. 551–569 CrossRefGoogle Scholar.

⁵³ Available at: {http://www.freedomhouse.org/}.

⁵⁴ Gibler, Douglas M., ‘Bordering on peace: Democracy, territorial issues, and conflict’, International Studies Quarterly, 51:3 (2007), pp. 509–532 Google Scholar; James, Patrick, Park, Johann, and Choi, Seung-Whan, ‘Democracy and conflict management: Territorial claims in the Western hemisphere revisited’, International Studies Quarterly, 50:4 (2006), pp. 803–817 CrossRefGoogle Scholar; Vasquez, John A., ‘Why do neighbors fight? Proximity, interaction, or territoriality’, Journal of Peace Research, 32:3 (1995), pp. 277–293 Google Scholar.

⁵⁵ See Stinnett, Douglas M., Tir, Jaroslav, Diehl, Paul F., Schafer, Philip, and Gochman, Charles, ‘The Correlates of War (COW) Project Direct Contiguity Data, Version 3.0’, Conflict Management and Peace Science, 19:2 (2002), pp. 59–67 Google Scholar. This definition means that two countries are considered neighbours if they share a land or river border, or if they are separated by no more than 400 miles of water. See also {http://www.correlatesofwar.org/cow2%20data/directcontiguity/dcv3desc.htm}.

⁵⁶ Maoz and Russett, ‘Normative and structural causes of democratic peace’.

⁵⁷ Regime change is defined as a change in the Polity Index of three points or more over a period of no more than three years.

⁵⁸ Available at: {http://hdr.undp.org/en/data}. The Human Development Index (HDI) does not cover every year of the period of interest. We used linear interpolation to fill in numbers for missing years, under the assumption that the key components of HDI – health, education and standard of living – tend to change only slowly.

⁵⁹ Available at: {http://data.worldbank.org/}.

⁶⁰ Gwartney, James, Hall, Joshua C., and Lawson, Robert, Economic Freedom of the World: 2010 Annual Report (Vancouver, BC: The Fraser Institute, 2010)Google Scholar; see also {http://www.freetheworld.com/}.

⁶¹ Waltz, Kenneth N., Theory of International Politics (New York: McGraw-Hill, 1979), p. 72 Google Scholar.

⁶² Mearsheimer, John J., The Tragedy of Great Power Politics (New York: Norton, 2001)Google Scholar.

⁶³ Singer, David J., Bremer, Stuart, and Stuckey, John, ‘Capability distribution, uncertainty, and major power war’, in Bruce Russett (ed.), Peace, War and Numbers (Beverly Hills, CA: Sage, 1972), pp. 19–48 Google Scholar; see also the Correlates of War Project, available at: {http://www.correlatesofwar.org/}.

⁶⁴ The recalculation of CINC scores is based on a prior division of the world into five geopolitically relevant regions: Europe (including Russia and the CIS countries); the Americas; Asia and Oceania (excluding the Middle East); sub-Saharan Africa; and the Middle East (including North Africa).

⁶⁵ Bremer, ‘Dangerous dyads’, p. 322.

⁶⁶ Rock, ‘Anglo–US relations, 1845–1930’; Rosato, ‘The flawed logic of the democratic peace theory’, pp. 599–600.

⁶⁷ Russett, Bruce and Deluca, Donald R., ‘Theater nuclear forces: Public opinion in Western Europe’, Political Science Quarterly, 98:2 (1983), pp. 179–196 Google Scholar.

⁶⁸ Available at: {http://www.heritage.org/research/reports/2006/05/global-us-troop-deployment-1950-2005}.

⁶⁹ Goldsmith, Benjamin E., ‘A universal proposition?: Region, conflict, war, and the robustness of the liberal peace’, European Journal of International Relations, 12:4 (2006), pp. 533–563 Google Scholar.

⁷⁰ Mearsheimer, The Tragedy of Great Power Politics.

⁷¹ See Clements, Ben, ‘Public opinion in Britain towards military action in Libya: a micro-level analysis’, Politics, 32:2 (2012), pp. 109–119 Google Scholar; Diez-Nicolas, Juan, ‘Cultural differences on values about conflict, war and Peace’, World Values Research, 3:1 (2010), pp. 1–19 Google Scholar; Torgler, Benno, ‘Why do people go to war?’, Defence and Peace Economics, 14:4 (2003), pp. 261–280 Google Scholar.

⁷² Diez-Nicolas, ‘Values about conflict, war and peace’.

⁷³ Inglehart, Puranen, and Welzel, ‘The individual-level basis of the long peace’, p. 432.

⁷⁴ Maoz and Russett, ‘Normative and structural causes of democratic peace’.

⁷⁵ This variable, which is computed based on the Correlates of War Project’s Interstate War Data, takes the value 1 if a country was on the losing side in the Second World War (and 0 otherwise); see Paez, Dario, Liu, James H., Techio, Elza, Slawuta, Patricia, Zlobina, Anya, and Cabecinas, Rosa, ‘“Remembering” World War II and willingness to fight: Sociocultural factors in the social representation of historical warfare across 22 societies’, Journal of Cross-Cultural Psychology, 39:4 (2008), pp. 373–380 Google Scholar.

⁷⁶ Data are from Stockholm Peace Research Institute, available at: {http://www.sipri.org/research/armaments/milex}.

⁷⁷ We coded the variable ourselves based on information from Internet sources, including the CIA World Factbook, available at: {https://www.cia.gov/library/publications/the-world-factbook/}; ChartsBin, available at: {http://chartsbin.com/} and a number of country-specific sources.

⁷⁸ The war measure is based on a variable from University of Uppsala and the Peace Research Institute in Oslo, which uses a threshold of 25 battle-related deaths in a year. We created a dummy taking the value 1 if a country had experienced war in the year in question or in the two previous years. (See {http://www.pcr.uu.se/research/ucdp/datasets/ucdp_prio_armed_conflict_dataset/}.) Our measure of militarised interstate disputes (MIDs) uses the average number of MIDs for the year in question and the previous two years. Data are from the Correlates of War Project, available at: {http://www.correlatesofwar.org/data-sets/MIDs}.

⁷⁹ Kant, Perpetual Peace, p. 54.

⁸⁰ Ibid.

⁸¹ Finnemore, Martha, The Purpose of Intervention: Changing Beliefs about the Use of Force (Ithaca, NY: Cornell University Press, 2003), p. 3 Google Scholar.

⁸² Eichenberg, ‘Citizen opinion on foreign policy and world politics’; Jentleson, Bruce W., ‘The pretty prudent public: Post post-Vietnam American opinion on the use of military force’, International Studies Quarterly, 36:1 (1992), pp. 49–73 Google Scholar; Jentleson, Bruce W. and Britton, Rebecca L., ‘Still pretty post-Cold War American public opinion on the use of military force’, Journal of Conflict Resolution, 42:4 (1998), pp. 395–417 Google Scholar.

⁸³ Hildebrandt, Timothy, Hillebrecht, Courtney, Holm, Peter M., and Pevehouse, Jon, ‘The domestic politics of humanitarian intervention: Public opinion, partisanship, and ideology’, Foreign Policy Analysis, 9:3 (2013), pp. 243–266 Google Scholar.