by Michael W. Doyle¹

Peace and democracy are just two sides of the same coin, it has often been said. In a speech before the British parliament in June of 1982, President Ronald Reagan proclaimed that governments founded on a respect for individual liberty exercise “restraint” and “peaceful intentions” in their foreign policy. He then, perhaps unaware of the contrast, announced a “crusade for freedom” and a “campaign for democratic development.”²

In making these claims the President joined a long list of liberal theorists (and propagandists) and echoed an old argument: the aggressive instincts of authoritarian leaders and totalitarian ruling parties make for war. Liberal states, founded on such individual rights as equality before the law, free speech and other civil liberties, private property, and elected representation are fundamentally against war, this argument asserts. When citizens who bear the burdens of war elect their governments, wars become impossible. Furthermore, citizens appreciate that the benefits of trade can be enjoyed only under conditions of peace. Thus, the very existence of liberal states, such as the United States, the European Union and others, makes for peace. And so peace and democracy are two sides of the same coin.

Building on a growing literature in international political science, I question the pacific liberal claim by identifying three distinct theoretical traditions of liberalism: liberal pacifism, liberal imperialism, and a liberal internationalism that combines elements of both the previous two.

Despite the contradictions of liberal pacifism and liberal imperialism, I find with Immanuel Kant and other liberal republicans that liberalism does leave a coherent legacy on foreign affairs. Liberal states are different. They are indeed peaceful. But they are also prone to make war. Liberal states, as Kant argued they would, have created a separate peace. They also, as he feared they might, have discovered liberal reasons for aggression. I conclude by arguing that the differences among liberal pacifism, liberal imperialism, and Kant’s liberal internationalism are not arbitrary. They are rooted in differing conceptions of the citizen and of societies and states.

Liberal pacifism

There is no canonical description of liberalism. What we tend to call liberal resembles a family portrait of principles and institutions, recognizable by certain characteristics – for example, a commitment to individual freedom, government through democratic representation, rights of private property, and equality of opportunity – that most liberal states share, although none has perfected them all. Joseph Schumpeter clearly fits within this family when he considers the international effects of capitalism and democracy.

Schumpeter’s “Sociology of Imperialisms,” which was published in 1919, made a coherent and sustained argument concerning the pacifying (in the sense of non-aggressive) effects of liberal institutions and principle.³ Unlike some of the earlier liberal theorists, who focused on a single feature, such as trade⁴ or failed to examine critically the arguments they were advancing, Schumpeter saw the interaction of capitalism and democracy as the foundation of liberal pacifism.

Capitalism, he suggests, produces an unwarlike disposition; its populace is “democratized, individualized, rationalized.”⁵ The people’s daily energies are daily absorbed in production. The disciplines of industry and the market train people in “economic rationalism;” the instability of industrial life necessitates calculation. Capitalism also “individualizes;” “subjective opportunities” replace the “immutable factors” of traditional, hierarchical society. Rational individuals demand democratic governance.

And democratic capitalism leads to peace. As evidence, Schumpeter claims that (1) throughout the capitalist world an opposition has arisen to “war, expansion, cabinet diplomacy;” (2) contemporary capitalism is associated with peace parties; and (3) the industrial worker of capitalism is “vigorously anti-imperialist.” In addition, (4) the capitalist world has developed the means of preventing war, such as the Hague Court, and (5) the least feudal, most capitalist society – the United States – has demonstrated the least imperialistic tendencies. (With a curious absence of irony he notes that the United States left over half of Mexico unconquered in the war of 1846-48.)

Schumpeter’s explanation for liberal pacifism was simple. Only war profiteers and military aristocrats gain from wars. No democracy would pursue a minority interest and tolerate the high costs of imperialism. When free trade prevails, “no class” gains from forcible expansion: “foreign raw materials and food stuffs are as accessible to each nation as though they were in its own territory. Where the cultural backwardness of a region makes normal economic intercourse dependent on colonization it does not matter, assuming free trade, which of the ‘civilized’ nations undertakes the task of colonization.”⁶

Liberal imperialism

In contradistinction to the pacific view of popular government, Thucydides and later Niccolò Machiavelli argue that not only are free republics not pacifistic, they are the best form of state for imperial expansion. Establishing a republic fit for imperial expansion is, moreover, the best way to guarantee the survival of a state.

Machiavelli’s republic is a classical, mixed republic. It is not a democracy, which he thought would quickly degenerate into a tyranny; nor is it founded on the modern liberal view of fundamental human rights. But it is characterized by popular liberty and political participation.⁷ The consuls serve as “kings;” the senate as an aristocracy managing the state, the people in the assembly as the source of strength.

Liberty results from the “disunion” – the competition and necessity for compromise required by the division of powers among senate, consuls and tribunes (the last representing the common people). Liberty also results from the popular veto. The powerful few, Machiavelli says, threaten tyranny because they seek to dominate; the mass demands not to be dominated. Their veto thus preserves the liberties of the state.⁸ But since the people and the rulers have different social characters, the people need to be “managed” by the few to avoid having their recklessness overturn or their fecklessness undermine the ability of the state to expand.⁹ Thus the senate and the consuls plan expansion, consult oracles, and employ religion to manage the resources that the energy of the people supplies.

Strength, and then imperial expansion, result from the way liberty encourages increased population and property, which grow when the citizens know that their lives and goods are secure from arbitrary seizure. Free citizens equip large armies and provide soldiers who fight for public glory and the common good, because they are in fact their own.¹⁰ Thus, if you seek the honor of having your state expand, Machiavelli advises, you should organize it as a free and popular republic like Rome, rather than as an aristocratic republic like Sparta or Venice. Expansion thus calls for a free republic.

“Necessity” – political survival – calls for expansion. If a stable aristocratic republic is forced by foreign conflict “to extend her territory, in such a case we shall see her foundations give way and herself quickly brought to ruin.”¹¹ If domestic security, on the other hand, prevails, “the continued tranquillity would enervate her, or provoke internal dissensions, which together, or either of them separately, will apt to prove her ruin.” Machiavelli therefore believes that it is necessary to take the constitution of Rome, rather than that of Sparta or Venice, as our model.

Hence liberal imperialism. We are lovers of glory, Machiavelli announces. We seek to rule, or at least to avoid being oppressed. In either case, we want more for ourselves and our states than just material welfare (materialistic monism). Because other states with similar aims thereby threaten us, we prepare ourselves for expansion. Because our fellow citizens threaten us if we do not allow them either to satisfy their ambition or to release their political energies through imperial expansion, we expand.

There is considerable historical evidence for liberal imperialism. Machiavelli’s (Polybius’) Rome and Thucydides’ Athens both were imperial republics in the Machiavellian sense.¹² The historical record of numerous United States interventions in the postwar period supports Machiavelli’s argument.¹³ But the current record of liberal pacifism, weak as it is, calls some of Machiavelli’s insights into question. To the extent that the modern populace actually controls (and thus unbalances) the mixed republic, their diffidence may outweigh elite (“senatorial”) aggressiveness.

We can conclude either that (1) liberal pacifism has at last taken over with the further development of capitalist democracy, as Schumpeter predicted it would; or (2) the mixed record of liberalism – pacifism and imperialism – indicates that some liberal states are Schumpeterian democracies while others are Machiavellian republics. But before we accept either conclusion, we must consider a third apparent regularity of modern world politics.

Liberal internationalism

Modern liberalism carries with it two legacies. They affect liberal states, not separately, according to whether they are pacifistic or imperialistic, but simultaneously.

The first of these legacies is the pacification of foreign relations among liberal states.¹⁴ During the nineteenth century, the United States and Great Britain engaged in nearly continual strife. But after the Reform Act of 1832 defined actual representation as the formal source of the sovereignty of the British parliament, Britain and the United States negotiated their disputes despite, for example, British grievances against the Northern blockade of the South, with which Britain had close economic ties. Despite severe Anglo-French colonial rivalry, liberal France and liberal Britain formed an entente against illiberal Germany before World War One. And in 1914-15, Italy, the liberal member of the Triple Alliance with Germany and Austria, chose not to fulfil its treaty obligations under the Triple Alliance to support its allies. Instead, Italy joined in an alliance with Britain and France that had the result of preventing it from having to fight other liberal states and then declared war on Germany and Austria. And despite generations of Anglo-American tension and Britain’s wartime restrictions on American trade with Germany, the United States leaned toward Britain and France from 1914 to 1917, before entering World War One on their side.

Beginning in the eighteenth century and slowly growing since then, a zone of peace, which Kant called the “pacific federation” or “pacific union,” began to be established among liberal societies. (More than fifty liberal states currently make up the union. Most are in Europe and North America, but they can be found on every continent.)

Here, the predictions of liberal pacifists are borne out: liberal states do exercise peaceful restraint and a separate peace exists among them. This separate peace provides a political foundation for the United States’ crucial alliances with the liberal powers (NATO, the alliances with Japan, Australia and New Zealand). This liberal alliance engendered the unbalanced, preponderance of resources that the “West” enjoyed during the Cold War. This foundation appears to be impervious to economic competition and personal quarrels with liberal allies. It also offers the promise of a continuing peace among liberal states. And, as the number of liberal states increases, it announces the possibility of global peace this side of the grave or world conquest.

Of course, the outbreak of war, in any given year, between any two given states, is a low probability event. But the occurrence of a war between any two adjacent states, considered over a long period of time, would be more probable. The apparent absence of war between liberal states, whether adjacent or not, for almost two hundred years may therefore have significance. Similar claims cannot be made for feudal, “fascist,” communist, authoritarian or totalitarian forms of rule;¹⁵ nor for pluralistic, or merely similar societies. More significant perhaps, is that when states are forced to decide on which side of an impending world war they will fight, liberal states wind up all on the same side, despite the complexity of the paths that take them there. These characteristics do not prove that the peace among liberals is statistically significant, nor that liberalism is the peace’s sole valid explanation.¹⁶ But they do suggest that we consider the possibility that liberals have indeed established a separate peace – but only among themselves.

Liberalism also carries with it a second legacy – international “imprudence.”¹⁷ Peaceful restraint only seems to work in the liberals’ relations with other liberals. Liberal states have fought numerous wars with non-liberal states.¹⁸

Many of these wars have been defensive, and thus prudent by necessity. Liberal states have been attacked and threatened by non-liberal states that do not exercise any special restraint in their dealings with liberal states. Authoritarian rulers both stimulate and respond to an international political environment in which conflicts of prestige, of interest, and of pure fear of what other states might do, all lead states toward war. War and conquest have thus characterized the careers of many authoritarian rulers and ruling parties – from Louis XIV and Napoleon Bonaparte to Benito Mussolini’s fascists, Adolf Hitler’s Nazis, and Joseph Stalin’s communists.

But we cannot simply blame warfare on the authoritarians or totalitarians, as many of our more enthusiastic politicians would have us do. Most wars arise out of calculations and miscalculations of interest, misunderstandings, and mutual suspicions, such as those that characterized the origins of World War One. But aggression by the liberal state has also characterized a large number of wars. Both France and Britain fought expansionist colonial wars throughout the nineteenth century. The United States fought a similar war with Mexico in 1846-48, waged a war of annihilation against the American Indians, and intervened militarily against sovereign states many times before and after World War Two. Liberal states invade weak non-liberal states and display striking distrust in dealings with powerful non-liberal states.¹⁹

Kant’s theory of liberal internationalism helps us understand these two legacies. The importance of Immanuel Kant as a theorist of international ethics has been well appreciated.²⁰ But Kant also has an important analytical theory of international politics. Perpetual Peace, written in 1795, helps us understand the interactive nature of international relations. Methodologically, he tries to teach us that we cannot study either the systemic relations of states or the varieties of state behavior in isolation from each other. Substantively, he anticipates for us the ever-widening pacification of a liberal pacific union, explains that pacification, and at the same time suggests why liberal states are not pacific in their relations with non-liberal states. Kant argues that perpetual peace will be guaranteed by the ever-widening acceptance of three “definitive articles” of peace. When all nations have accepted the definitive articles in a metaphorical “treaty” of perpetual peace he asks them to sign, perpetual peace will have been established.

First, republican governments, he argues, tame the aggressive interests of absolutist monarchies and ingrain the habit of respect for individual rights. Wars then appear as direct charges on the people’s welfare that he and the other liberals thought them to be. Yet these domestic republican restraints do not end war. If they did, liberal states would not be warlike, which is far from the case. They do introduce republican caution, Kant’s “hesitation,” in place of monarchical caprice. Liberal wars are only fought for popular, liberal purposes. The historical liberal legacy is laden with popular wars fought to promote freedom, protect private property or support liberal allies against non-liberal enemies.²¹

Second, in order to see how the pacific union removes the occasion of wars among liberal states and not wars between liberal and non-liberal states, we need to shift our attention from constitutional law to international law, Kant’s second source. Complementing the constitutional guarantee of caution, international law adds a second source – a guarantee of respect. The separation of nations is reinforced by the development of separate languages and religions. These further guarantee a world of separate states—an essential condition needed to avoid a “global, soul-less despotism.” Yet, at the same time, they also morally integrate liberal states “as culture grows and men gradually move towards greater agreement over their principles, they lead to mutual understanding and peace.”²² As republics emerge (the first source) and as culture progresses, the established practice of recognized legal rights resting on an understanding of the legitimate rights of all citizens and of all republics comes into play; and this, now that caution characterizes policy, sets up the institutional and moral foundations for the liberal peace. Correspondingly, international law highlights the importance of Kantian publicity.

Domestically, publicity helps ensure that the officials of republics act according to the principles they profess to hold just and according to the interests of the electors they claim to represent. Internationally, free speech and the effective communication of accurate conceptions of the political life of foreign peoples is essential to establish and preserve the understanding on which the guarantee of respect depends. Domestically, just republics, which rest on consent, then presume foreign republics to be also consensual, just, and therefore deserving of accommodation. The recognition of legitimate rights and the experience of cooperation helps engender further cooperative behavior when the consequences of state policy are unclear but (potentially) mutually beneficial. At the same time, liberal states assume that non-liberal states, which do not rest on free consent, are not just. Because non-liberal governments are perceived to be in a state of aggression with their own people, their foreign relations become for liberal governments deeply suspect. In short, fellow liberals benefit from a presumption of amity; non-liberals suffer from a presumption of enmity. Both presumptions may be accurate. Each, however, may also be self-fulfilling.

Democratic liberals do not need to assume either that public opinion rules foreign policy or that the entire governmental elite is liberal. It can assume that the elite typically manages public affairs but that potentially non-liberal members of the elite have reason to doubt that antiliberal policies would be electorally sustained and endorsed by the majority of the democratic public.

Third and lastly, cosmopolitan law adds material incentives to moral commitments. The cosmopolitan right to hospitality permits the “spirit of commerce” sooner or later to take hold of every nation, thus creating incentives for states to promote peace and to try to avert war. Liberal economic theory holds that these cosmopolitan ties derive from a cooperative international division of labor and free trade according to comparative advantage. Each economy is said to be better off than it would have been under autarky; each thus acquires an incentive to avoid policies that would lead the other to break these economic ties. Since keeping open markets rests upon the assumption that the next set of transactions will also be determined by legal rights and agreed upon prices rather than coercion, a sense of mutual security is vital to avoid security-motivated searches for economic autarky. Thus avoiding a challenge to another liberal state’s security or even enhancing each other’s security by means of alliance naturally follows economic interdependence.

A further cosmopolitan source of liberal peace is that the international market removes difficult decisions of production and distribution from the direct sphere of state policy. A foreign state thus does not appear directly responsible for these outcomes; states can stand aside from, and to some degree above, these contentious market rivalries and be ready to step in to resolve crises. The interdependence of commerce and the international contacts of state officials help create crosscutting transnational ties that serve as lobbies for mutual accommodation.²³ According to modern liberal scholars, international financiers and transnational and transgovernmental organizations create interests in favor of accommodation. Moreover, their variety has ensured no single conflict sours an entire relationship by setting off a spiral of reciprocated retaliation. Trust, property rights and mutual expectation of the rule of law make economic and other disputes easier to settle. Conversely, a sense of suspicion, such as that characterizing relations between liberal and non-liberal governments, can exacerbate disputes and lead to restrictions on the range of contacts between societies and this can increase the prospect that a single conflict will determine an entire relationship.

No single constitutional, international or cosmopolitan source alone is sufficient. Kantian theory is neither solely institutional nor solely ideological, nor solely economic. But together, and only together do the three specific strands of liberal institutions, liberal ideas, and the transnational ties that follow from them plausibly connect the characteristics of liberal polities and economies with sustained liberal peace. But in their relations with non-liberal states, liberal states have not escaped from the insecurity caused by anarchy in the world political system considered as a whole. Moreover, the very constitutional restraint, international respect for individual rights, and shared commercial interests that establish grounds for peace among liberal states establish grounds for additional conflict in relations between liberal and non-liberal societies.

Comparisons

Much of the debate on the democratic peace or liberal pacifism isolates one feature of democracy or liberalism and then tests it against the historical record. It is thus worth stressing that Kant’s theory rejects that approach.²⁴ He presents each of the three “definitive articles” as necessary conditions that and only together establish a sufficient condition of establishing a pacific union.

Representation or democracy (the so-called domestic “structural” causes of the democratic peace) only ensures that foreign policy reflects the preferences of the median voter, whatever they may be. If those preferences are rational egositic, then however rational or powerful the state may be, it will only be pacific to the extent that a particular bilateral peace produces greater material benefits than would aggression (discounting but still counting all systemic and temporal effects). This is a weak reed for a wealthy, resource rich or strategically vital, but very weak democratic state to rely upon in its relations with powerful and also democratic states.²⁵

A related objection applies to purely “normative” explanations of the liberal peace. The norms, to the extent they are normative, apply to all statespersons as moral agents, as human beings, anywhere, whatever their state structure. Yet states other than liberal states do not maintain peace (and liberals maintain peace only with each other).²⁶ In short, Kant’s argument for the combined effect of structures, norms, and interests warrants our attention.

In order to sort out the varied legacy of liberalism on international relations, we should also recall that Kant’s liberal internationalism, Machiavelli’s liberal imperialism, and Schumpeter’s liberal pacifism rest on fundamentally different views on the nature of man, the state, and international relations.²⁷ Schumpeter’s man is rationalized, individualized, and democratized. He is also homogenized, pursuing material interests “monistically.” Since his material interests lie in peaceful trade, he and the democratic state that he and his fellow citizens control are pacifistic. Machiavelli’s citizens are splendidly diverse in their goals, but they are fundamentally unequal in them as well, seeking to rule or fearing being dominated. Extending the rule of the dominant elite, or avoiding the political collapse of their state, each call for imperial expansion.

Kant’s citizens, too, are diverse in their goals, and they are individualized and rationalized. But most importantly, they are capable of appreciating the moral equality of all individuals and of treating other individuals as ends rather than as means. The Kantian state thus is governed publicly according to law, as a republic. Kant’s is the state that – formally, legally—solves the problem of governing individualized equals whether they are the “rational devils” he says we often find ourselves to be or the ethical agents we can and should become.

“In order to organize a group of rational beings who together require universal laws for their survival, but of whom each separate individual is secretly inclined to exempt himself from them, the constitution must be so designed so that, although the citizens are opposed to one another in their private attitudes, these opposing views may inhibit one another in such a way that the public conduct of the citizens will be the same as if they did not have such evil attitudes.”²⁸

Unlike Machiavelli’s republics, Kant’s republics are capable of achieving peace among themselves because they exercise democratic caution and because they are capable of appreciating the international rights of foreign republics. These international rights of republics derive from the representation of foreign individuals, who are our moral equals. Unlike Schumpeter’s capitalist democracies, Kant’s republics remain in a state of war with non-republics. Liberal republics see themselves as threatened by aggression from non-republics that are not constrained by representation. And even though wars often cost more than the economic return they generate, liberal republics also are prepared to protect and promote – sometimes forcibly – democracy, private property, and the rights of individuals overseas against non-republics which, because they do not authentically represent the rights of individuals, have no rights to non-interference. These wars may liberate oppressed individuals overseas; they can also generate enormous suffering.

Preserving the legacy of the liberal peace without succumbing to the legacy of liberal imprudence is both a moral and a strategic challenge. The near certainty of mutual devastation resulting from a nuclear war between the superpowers has created a “crystal ball effect” which has helped to constrain the tendency toward miscalculation that was present at the outbreak of so many wars in the past. But this “nuclear peace” appeared to have been limited to the superpowers. It did not curb military interventions in the Third World. Moreover, it is subject to a desperate technological race designed to overcome its constraints and to crises that have pushed even the superpowers to the brink of war. We must still reckon with the war fevers and moods of appeasement that have almost alternately swept liberal democracies.

Yet restraining liberal imprudence, whether aggressive or passive, may not be possible without threatening liberal pacification. Improving the strategic acumen of our foreign policy calls for introducing steadier strategic calculations of the long run national interest and more flexible responses to changes in the international political environment. Constraining the indiscriminate meddling of our foreign interventions calls for a deeper appreciation of the “particularism of history, culture, and membership.”²⁹ However, both the improvement in strategy and the constraint on intervention, in turn, seem to require an executive freed from the restraints of a representative legislature in the management of foreign policy and a political culture indifferent to the universal rights of individuals. And these, in their turn, could break the chain of constitutional guarantees, the respect for representative government, and the web of transnational contact that have sustained the pacific union of liberal states.

Perpetual peace, Kant says, is the endpoint of the hard journey his republics will take. The promise of perpetual peace, the violent lessons of war, and the experience of a partial peace are proof of the need for and the possibility of world peace. They are also the grounds for moral citizens and statesmen to assume the duty of striving for peace.

1. This essay draws on parts of Michael W. Doyle’s Ways of War and Peace. 1997. New York: W.W. Norton.

Michael W. Doyle is the Harold Brown Professor at Columbia University in the School of International and Public Affairs and Columbia Law School.

Professor Doyle previously has taught at the University of Warwick (United Kingdom), Johns Hopkins University and Princeton University. His publications include Ways of War and Peace (W.W. Norton); Empires (Cornell University Press); UN Peacekeeping in Cambodia: UNTAC’s Civil Mandate (Lynne Rienner Publishers); Keeping the Peace (Cambridge University Press) which he edited with Ian Johnstone and Robert Orr; Peacemaking and Peacekeeping for the New Century (Rowman and Littlefield) edited with Olara Otunnu; New Thinking in International Relations Theory (Westview) edited with John Ikenberry; Escalation and Intervention: Multilateral Security and Its Alternatives (Westview Press/United Nations Association) edited with Arthur Day; and Alternatives to Monetary Disorder (Council on Foreign Relations/McGraw Hill) which he wrote with Fred Hirsch and Edward Morse.

He recently served as Assistant Secretary-General and Special Adviser to United Nations Secretary-General Kofi Annan. His responsibilities in the Secretary-General’s Executive Office included strategic planning, outreach to the international corporate sector (the “Global Compact”) and relations with Washington. He is currently chairman of the Academic Council of the United Nations Community. He was the Director of the Center of International Studies of Princeton University and chairman of the Editorial Board and the Committee of Editors of World Politics. He was the vice-president and senior fellow of the International Peace Academy and is now a member of its board of directors. He has also served as a member of the External Research Advisory Committee of the UNHCR, the Advisory Committee of the Lessons-Learned Unit of the Department of Peace-Keeping Operations (UN), and is a member of the Council on Foreign Relations, New York. In 2001, he was elected a fellow of the American Academy of Arts and Sciences.

Michael Doyle is married, has a daughter and lives in Philadelphia and New York.

2. Reagan, Ronald. 1983/1984. “Peace and National Security,” televised address to the nation, Washington D.C., March 23, 1983, p. 40 in the U.S. State Department, Realism, Strength, Negotiation, May 1984.

3. Schumpeter, Joseph. 1950. Capitalism, Socialism, and Democracy. New York: Harper Torchbooks. Doyle, Michael W. 1986. “Liberalism and World Politics,” American Political Science Review, vol. 80, no. 4 (December), pp. 1151-1169.

4. Montesquieu, Charles de Secondat, Baron of. 1748/1966. Spirit of the Laws. New York: Hafner, bk. 20, ch. 1.

5. Schumpeter, Joseph. 1955. “The Sociology of Imperialism.” Imperialism and Social Classes. Cleveland: World Publishing, p. 68.

6. Ibid. pp. 75-76. A study by R.J. Rummel of “libertarianism” and international violence is the closest test that Schumpeterian pacifism has received (1983). “Free” states (those enjoying political and economic freedom) have considerably less conflict at the level of economic sanctions or above (more violent) than “non-free” states. The free, the partly free (including the democratic socialist countries such as Sweden), and the non-free accounted for .24, .26 and .61 of the violence, respectively. These correlations are impressive, but not conclusive for the Schumpeterian thesis. The data set is limited, in this test, to 1976-1980. It includes, for example, the Russian-Afghan War, the Vietnamese invasion of Cambodia, China’s invasion of Vietnam and Tanzania’s invasion of Uganda, but just misses the U.S. quasi-covert intervention in Angola (1975) and the not so covert war against Nicaragua (1981). More importantly, it excludes the cold war period with its numerous interventions and the long history of colonial wars (the Boer War, the Spanish American War, the Mexican Intervention, etc.) that marked the history of liberal, including democratic capitalist states. See Rummel, Rudolph J. 1983. “Libertarianism and International Violence.” Journal of Conflict Resolution, vol. 27, pp. 27-71.

7. Machiavelli, Niccolò. 1950. The Prince and the Discourses, trans. Luigi Ricci and Christian Detmold, ed. Max Lerner. New York: Modern Library, bk. I, ch. 2, p. 112; Mansfield, Harvey C. 1970. “Machiavelli’s New Regime.” Italian Quarterly, vol. 13, pp. 63-95; Skinner, Quentin. 1981. Machiavelli. New York: Hill and Wang, ch. 3; Huliung, Mark, 1983. Citizen Michavelli. Princeton: Princeton University Press, ch. 2.

8. Ibid, bk. I, ch. 5, p. 122.

9. Ibid, bk. I, ch. 53, pp. 249-250.

10. Ibid, bk. II, ch. 2, pp. 287-290.

11. Ibid, bk. I, ch. 6, p. 129.

12. Thucydides, 1954/1972. The Peloponnesian War, trans. Rex Warner, intro. M.I. Finley. Harmondsworth, England: Penguin, bk. 6.

13. Aron, Raymond. 1973. The Imperial Republic, trans. Frank Jellinek. Englewood Cliffs, New Jersey: Prentice Hall, chs. 3-4; Barnet, Richard. 1968. Intervention and Revolution: The United States in the Third World. New York: Meridian, ch. 11.

14. Clarence Streit (1938. Union Now: A Proposal for a Federal Union of the Leading Democracies. New York: Harper, pp. 88, 90-92) seems to have been the first to point out (in contemporary foreign relations) the empirical tendency of democracies to maintain peace among themselves, and he made this the foundation of his proposal for a (non-Kantian) federal union of the leading democracies of the 1930s. In a very interesting book, Ferdinand Hermens (1944) explored some of the policy implications of Streit’s analysis. D.V. Babst (1972. “A Force of Peace.” Industrial Research, vol. 14 (April), pp. 55-58) performed a quantitative study of this phenomenon of “democratic peace.” And R.J. Rummel did a similar study of “libertarianism” (in the sense of laissez faire) focusing on the post-war period (1983), which drew on an unpublished study (Project No. 48) noted in Appendix I:7.5 (1979, p. 386). I use “liberal” in a wider (Kantian) sense in my discussion of this issue in (1983). In that essay, I survey the period from 1790 to the present, and find no war among liberal states.

15. Doyle, Michael W. 1983. “Kant, Liberal Legacies and Foreign Affairs,” Part 1 and 2, Philosophy and Public Affairs, vol. 12, nos. 3-4 (Summer and Fall), p. 222.

16. Babst (ibid, “A Force for Peace,” 1972) did make a preliminary test of the significance of the distribution of alliance partners in World War One. He found that the possibility that the actual distribution of alliance partners could have occured by chance was less than 1% (p. 56). But this assumes that there was an equal possibility that any two nations could have gone to war with each other; and this is a strong assumption. The most thorough statistical demonstration of the significance of the liberal peace, controlling for alliance patterns, proximity, economic interdependence, etc. can be found in Zeev Maoz and Bruce Russett, “Alliance, Contiguity, Wealth, Political Stability: Is the Lack of Conflict Among Democracies a Statistical Artifact,” International Interactions, vol. 17, no. 3 (1992), pp. 245-267.

17. Hume, David. 1752/1963. “Of the Balance of Power,” Essays: Moral, Political, and Literary. Oxford: Oxford University Press, pp. 346-347.

18. Small, Melvin and Singer, J. David. 1976. “The War-proneness of Democratic Regimes.” Jerusalem Journal of International Relations, vol. 50, no. 4 (Summer), pp. 50-69.

19. Op. cit. 1983. “Kant, Liberal Legacies.”

20. Armstrong, A.C. 1931. “Kant’s Philosophy of Peace and War.” Journal of Philosophy, vol. 28, pp. 197-204; Friedrich, Karl. 1948. Inevitable Peace. Cambridge, Mass.: Harvard University Press; Waltz, Kenneth. 1962. “Kant, Liberalism, and War.” American Political Science Review, vol. 56, pp. 331-340; Hoffmann, Stanley. 1965. The State of War. New York: Praeger; Hinsley, F.H. 1967. Power and the Pursuit of Peace. Cambridge, England: Cambridge University Press, ch. 4; Hassner, Pierre. 1972. “Immanuel Kant,” in Leo Strauss and Joseph Cropsey, eds., History of Political Pihlosophy. Chicago: Rand McNally; Galston, William. 1975. Kant and the Problem of History. Chicago: University of Chicago Press; Gallie, W. 1978. Philosophers of Peace and War. New York: Cambridge University Press, ch. 1; Williams, Howard. 1983. Kant’s Political Philosophy. Oxford: Basil Blackwell.

21. Kant regards these wars as unjust and warns liberals of their susceptibility to them (Perpetual Peace, in 1970, p. 106). At the same time, he argues that each nation “can and ought to” demand that its neighboring nations enter into the pacific union of liberal states (p. 102).

22. Op. cit., Kant. 1970, p. 114.

23. See for example, Russett, Bruce and O’Neal, John, Triangulating Peace: Democracy, Interdependence, and International Organizations, New York: W.W. Norton, 2000.

24. A useful survey of that literature can be found in Harvey Starr, “Why Don’t Democracies Fight One Another? Evaluating the Theory-Findings Feedback Loop,” Jerusalem Journal of International Relations, vol. 14, no. 4 (1992), pp. 41-57.

25. Lake, David. 1992. “Powerful Pacifists: Democratic States and War,” American Political Science Review, vol. 86, no. 1 (March 1992), pp. 24-37.

26. Maoz, Zeev and Russett, Bruce. “Alliance, Contiguity, Wealth and Political Stability: Is the Lack of Conflict among Democracies a Statistical Artifact?” International Interactions, vol. 17, no. 3. pp. 245-268.

27. For a comparative discussion of the political foundations of Kant’s ideas see Shklar, Judith. 1984. Ordinary Vices. Cambridge, Mass.: Harvard University Press, pp. 232-238.

28. Kant, Immanuel. 1970. Kant’s Political Writings, ed. Hans Reiss and trans. H.B. Nisbet. Cambridge: Cambridge University Press, England, p. 113.

29. Walzer, Michael. 1983. Spheres of Justice. New York: Basic Books, p. 5.

First published 22 June 2004