Kant and the End of War: A Critique of Just War Theory , Howard Williams (New York: Palgrave Macmillan, 2012), 216 pp., $90 cloth.

Kant and Cosmopolitanism: The Philosophical Ideal of World Citizenship, Pauline Kleingeld (New York: Cambridge University Press, 2012), 215 pp., $90 cloth.

Since the last decade of the twentieth century, Immanuel Kant has become central to academic discussions of international relations for various reasons, including the end of the cold war (which renewed many people’s hopes for worldwide peace and democracy) and the publication of writings by the prominent neo-Kantians Jürgen Habermas and John Rawls and their followers and critics, as well as by a number of Kant scholars writing about war, humanitarian intervention, democracy, international law, peace, and cosmopolitanism. Kant and the End of War, by Howard Williams, and Kant and Cosmopolitanism, by Pauline Kleingeld, are new books by two of the foremost contemporary scholars of Kant’s political philosophy, and the theme of international peace is central to both.

As Howard Williams notes, “Kant has simultaneously earned the reputation of both being an advocate of peace and a source of universalistic political ambitions that inevitably lead to war between the West and ‘the rest’” (pp. 2-3). Williams himself interprets Kant’s political philosophy as aiming “in a consistent and principled way towards eternal peace” (p. 3). He discusses Kant’s criticisms of the early modern just war theorists Grotius, Vattel, and Pufendorf, whom Kant famously called “sorry comforters,” and argues that Kant would similarly criticize contemporary just war theorists for “too lightly condemn[ing] humankind to a future of ever recurrent war” (p. 9).

Pauline Kleingeld aims to provide a comprehensive account of the cosmopolitan aspects of Kant’s thought, including his views about free trade, patriotism, and race. As she explains, cosmopolitan theorists have defended various moral and political positions, all of which endorse some conception of world citizenship; however, some construe this idea literally while others construe it as a “structuring metaphor or model” (p. 4). Kant develops a conception of the moral and cultural aspects of world citizenship, and also the global institutional arrangements necessary for realizing a genuine cosmopolitan condition (p. 3). Kleingeld sets Kant’s work in the context of the wider debate about cosmopolitanism that took place in German-speaking Europe in the last quarter of the eighteenth century. She argues that Kant changed his mind radically during the mid-1790s, and that the final form of his cosmopolitan political philosophy is rich and “much more coherent than is usually thought” (p. 5).

Although Williams does not say much about cosmopolitanism in his book, and Kleingeld does not say much about war in hers, their views intersect at certain points. Both authors offer interpretations of Kant’s philosophy of international law, explain its relevance to contemporary debates, and discuss Rawls’s conception of international justice and human rights (“the Law of Peoples”). However, their views about the Law of Peoples differ, as do their views about Kant’s philosophy of international law. Williams understands Kant’s ideal international order as a pacific league or federation without coercive powers, and he takes Rawls to advocate a similar ideal. Kleingeld, disputing what she terms “the standard interpretation” of Kant, characterizes Kant’s ideal as a federative state with coercive powers, and criticizes Rawls for advocating (as she sees it) only a pacific league or weak federation.

Williams presents his book primarily as a critique of the Western tradition of theorizing about the (in)justice of war and a challenge to those who think war is ever justifiable. In the first six of the book’s seven chapters, Williams briefly explains Kant’s views about philosophy and international law, and discusses in detail Kant’s views about war. He argues against Kant scholars Brian Orend and Susan Shell, who claim that Kant endorsed a modified just war theory. In the seventh chapter Williams criticizes four other contemporary writers (Michael Walzer, Jean Elshtain, James Turner Johnson, and John Rawls) by pointing out ways in which their views about war seem to him un-Kantian.

In Williams’s reading of Kant, war can never be fully just; any system of international law permitting war requires reform; and, under reformed international law, there would be no just war (p. 103). Although Kant is “committed to a cosmopolitan outlook which pays heed to the abuse of rights in all parts of the world,” his conception of a reformed international law rules out foreign intervention except where a state’s “sovereign power” has collapsed (pp. 7-8). Disagreeing with Orend and Shell, Williams contends that Kant rejects the idea that a state has a right to undertake a preemptive attack on a hostile state that threatens but has not yet violated the other state’s rights.

Williams acknowledges Kant’s view that it is obligatory for states in an international state of nature (that is, prior to the establishment of international law) to unite against an “unjust enemy” (that is, an aggressive state that refuses to regard itself as bound by any moral constraints) and, if they defeat it, to give it a new constitution. However, he emphasizes that Kant casts doubt on both the concept of an unjust enemy and the concept of a just enemy (pp. 102-103). Kant argued that since a state of nature is itself a condition of injustice, the concept of an unjust enemy cannot derive from a rule providing criteria for just war in the international state of nature; yet he also said that the concept of a just enemy makes little sense: “A just enemy would be one that I would be doing wrong by resisting; but then he would also not be my enemy” (The Metaphysics of Morals, VI: 350). According to Williams, Kant regarded “unjust enemy” states as worse only in degree, not kind, than states led by politicians who are less completely cynical but still strategically minded (p. 107).

Williams thinks Rawls’s Law of Peoples “too readily grants the ‘right’ to war in self defense,” and “accepts too readily that wars will occur” (pp. 162-63). In particular, Williams objects that Rawls “provides the political leader with the terminology of ‘outlaw states’ and . . . ‘self-defense’” (pp. 162–63). He worries that despite “Rawls’ emphasis that war should only be declared as a last resort . . . his formulation is sufficiently loose to encompass the . . . unjustifiable action taken against the Iraqi state in 2003” (p. 163).

Williams’s criticisms of the Law of Peoples are puzzling given that Rawls’s views on war and the ideal international order closely resemble those of Kant. Williams interprets Kant as arguing that states must seek to form “a peaceful union of peoples” that would ideally become a worldwide civil federation; that direct interference in the affairs of member states should be avoided; and that there should be no crusade to enroll nonmembers (pp. 98, 111). Williams acknowledges that Kant is not a pacifist, but he emphasizes Kant’s view that since states are obligated to establish and sustain a peaceful union, their right of war in self-defense must be conceived “as part of [their] role in an emerging federation of peaceful states.” Furthermore, “the prosecution of a war is hedged in by an equally important proviso to sustain such a union” (pp. 98, 169). On all of these points, Rawls’s Law of Peoples resembles Kant’s views.

Kleingeld focuses not on war but on Kant’s cosmopolitan ideals. She contends that Kant advocates the establishment of a state-like federative republic of republics with coercive authority, yet also argues that a voluntary league without coercive powers must be the first step on the road toward such a federation (pp. 43–44, 69,188). In Kleingeld’s reading of Kant, although the only form of state compatible with each individual’s fundamental right to freedom is a republican state in which citizens give themselves laws through their representatives, the people of any kind of state should be recognized as politically autonomous and should be respected as such, since every state embodies the rule of law, even if very imperfectly. While individual human beings are in the original state of nature, the rule of law does not exist; however, in an international state of nature (prior to the establishment of an international legal order), the rule of law already exists within each state. Kleingeld argues that coercing a state into a federation would be wrong because it would be paternalistic. A hegemonic, despotic federation would quash rights secured within the individual states; and a nonfederal world state incorporating all states into one would be (as Kant puts it) a “soulless despotism.” Therefore, advancement toward a condition in which all rights would be secure and peace would be perpetual requires establishing a federation non-coercively (pp. 48, 54, 56).

As Kleingeld explains, Kant argues that human self-interest moves states internally in the direction of a republican government, and that republics, in contrast to despotic states, naturally tend toward peace, since the citizens have the power to decide whether or not to go to war. Consequently, they will seldom favor starting wars because offensive wars are not in their interest, partly because they must do the fighting. Kant thought that a voluntary league would contribute to progress toward the ultimate goal of a strong international federation by reducing warfare and increasing stability. This would permit the internal development of states (including the education and enlightenment of their populations and the reform of their political institutions), which would in turn strengthen the peace process; and once agreement on universalist normative principles emerged, a voluntarily created federative republic of republics could be actively pursued (pp. 65–67). Thus, Kleingeld contends that Kant’s republicanism “rules out the coercive establishment of a world state, on the one hand, and supports the feasibility of a strong international federation, on the other” (p. 49).

Rawls says he “follows Kant’s lead” in rejecting world government in the sense of “a unified political regime with the legal powers normally exercised by central governments” (The Law of Peoples, 1999, p. 36). In Kleingeld’s view, “what is missing in The Law of Peoples is the ideal of a lawful and enforceable global arbitration of conflicts” in the form of “a world federation of states with coercive powers” (pp. 188–89). Kleingeld thinks not only that Kant advocated such a federation but also that he was right to do so. She contends that a league of republics providing nonenforceable arbitration would have “no real mechanism to settle disputes” among them (p. 189). Kleingeld’s objection is not that Kant would oppose the kind of global order she thinks Rawls advocates, but instead that Kant did, and Rawls did not, also advocate the subsequent development of a strong global federation of states, which would become possible only after a league or congress of states (or, to use Rawls’s term, a “Society of Peoples”) had been established.

Kleingeld also construes Rawls as arguing “that global democratization would be enough to durably do away with war,” and criticizes this view (p. 69). Yet, she notes “the emphasis [Kant] places on the self-legislation of peoples,” and praises Habermas for agreeing with Kant that “the existing states should not be dissolved in a hegemonic world state but integrated into a global federative constitutional framework” (p. 191). She also contends that “because states are ideally conceived as self-legislating peoples, any form of federation can be the result only of a democratic decision on the part of the peoples involved” (p. 190). Thus, Kleingeld’s criticisms of Rawls’s views about international law and peace are not fully clear; more discussion is required, especially about democracy (domestic as well as international or global), state sovereignty, the possible forms of confederations and federations, and the moral permissibility of various ways of establishing them.

Both Kant and the End of War and Kant and Cosmopolitanism are intellectually stimulating and enjoyable to read. Each offers an explanation of Kant’s political philosophy for readers unfamiliar with it, and each valuably illuminates it. In this way, both books provide the important service of enabling readers to appreciate and critically analyze contemporary political theorists’ various uses of Kant’s thought.



—ALYSSA R. BERNSTEIN

Alyssa R. Bernstein is an associate professor of philosophy at Ohio University.