The Theory of Aggression
Walzer’s central claim with regard to jus ad bellum is that starting a war is unjust: because people have individual rights to life and liberty, all just wars are defensive ones fought to vindicate those rights. That is to say, aggression is unjust, and defense against it – whether on the part of self or other – constitutes a just cause. Almost all just-war theory now follows Walzer in holding that just wars are defensive, whereas in the traditional view, there was some possibility of both sides being partially justified – having “comparative justice” of cause (for discussion, Coates 2016: 162–83).
Walzer’s position has proven controversial, however, in terms of how he defines aggression. He insists that it means the use of force across national boundaries, and so implies that war should be understood, in the first instance, as armed conflict between different states. On Walzer’s account, states have rights to political sovereignty and territorial integrity, and aggression is the violation of those rights (Walzer 2015a: 51–3). This was the most immediately controversial argument in Wars: it led critics to argue that Walzer’s theory would allow states to violate individual rights with impunity (Wasserstrom 1978, Doppelt 1978, Beitz 1979, Luban 1980a). Some recent just-war theorists have used the foundation in human rights to model just wars on police action (see especially Rodin 2002, McMahan 2009). The central ethical question that Walzer’s theory raises is: how does Walzer get from the notion that just wars are fought in defense of individual rights to the position that states have rights against which acts of aggression are committed?
Walzer grounds the rights of states on the rights of individual citizens by means of what he calls the “legalist paradigm”: crimes of war are understood by virtue of a “domestic analogy” with crimes in civil society (Walzer 2015a: 58). Just as individuals have rights of self-defense, so too do states, which are entitled to vindicate their rights because otherwise there would be no international society but either war or tyranny. For Walzer, the grounding of state rights is the international society of states, where the normative purpose of states is to defend rights. Defense against aggression in international politics consists in a self-help system, because in the absence of an international police force, states have “police powers” to defend themselves and other states against aggression (59). This account is analogous to John Locke’s famous notion of executive power to punish offenders against the law of nature in a state of nature (Locke 1988: 269–78). Walzer draws two conclusions. The first is that there is a presumption in favor of resistance to aggression: while states may choose to surrender, the importance of maintaining international society suggest that aggression ought to be deterred and the rights of states defended. This means relaxing the principle of reasonable hope of success to allow defense against a powerful aggressor. Second, Walzer concludes that no war is just on both sides, because no war can break out without an act of aggression. As all wars contain an aggressor, and as aggression is unjustified, it follows that in no war do both sides have a just cause. However, as David Rodin notes, it may not always be obvious which state is the aggressor (Rodin 2002: 191–4).
Walzer summarizes the theory of aggression in six propositions:
1. There exists an international society of independent states … 2. This international society has a law that establishes the rights of its members – above all, the rights of territorial integrity and political sovereignty … 3. Any use of force or imminent threat of force by one state against the political sovereignty or territorial integrity of another constitutes aggression and is a criminal act … 4. Aggression justifies two kinds of violent response: a war of self-defense by the victim or a war of law enforcement by the victim and any other member of international society … 5. Nothing but aggression can justify war … 6. Once the aggressor has been militarily repulsed, it can also be punished.
(Walzer 2015a: 61–3)5
These propositions sum up Walzer’s theory of jus ad bellum. They suggest that, although states exist to protect individual rights, states and not individuals are the key actors in international politics, because without states and state rights, people cannot build a “common life” (61). The notion of the common life, drawn from his critique of the US war in Vietnam, is of the utmost importance to Walzer’s just-war theory. It is often taken as a departure from Walzer’s insistence that just-war theory is grounded in individual rights. However, in Walzer’s theory, the rights to membership in a community and to participation in a common life are crucial individual rights (Walzer 1980a: 233–4) that mandate a protected space for communal self-determination, the violation of which is the only just cause for war. On Walzer’s account, the pluralist world order reflects the importance of a common life, which gives meaning to people via individual communities’ construction of sentiment, convention, and political friendship, and gives even freedom its significance (233). It is because states protect a common life that they have rights.
It is important to note that, on Walzer’s account, while aggression is the only legitimate justification for war, aggression does not necessarily lead to war. He insists that victims of aggression do have a right to appease their aggressors (Walzer 2015a: 69), because war causes untold death and destruction – this is the kernel of truth in the realist doctrine that “war is hell.” However, appeasement is morally acceptable only when the aggressor is a conventional great power – the sort of state “whose government strives to press its boundaries or its sphere of influence outward, a little bit here, a little bit there” (69). Faced with such a threat, those threatened have a right to resist, but not a duty. The choice is theirs. Against a government committed to “the continual use of violence … a policy of genocide, terrorism, and enslavement,” on the other hand, appeasement must be rejected as “a failure to resist evil in the world” (69). Again, Walzer’s example of evil is Nazism: he distinguishes between the appeasement of Nazi Germany’s demands over the Sudetenland in 1938 and the Soviet invasion of Finland a year later (68–72), suggesting that it was morally necessary to resist the Nazis but that Finland would have been entitled to concede some of Stalin’s demands. Using the Nazis as the epitome of an exceptional regime that must be resisted at all costs is typical of Walzer, who had argued some years earlier that what made World War II the epitome of a just war from the Allied perspective was that the Nazis represented “an ultimate threat to everything decent in our lives” (Walzer 1971b: 5, a passage repeated almost verbatim at Walzer 2015a: 252). What makes Nazism exceptional even in the long history of human brutality is, Walzer suggests, that it both constituted a threat to “civilization itself” (Walzer 1971b: 18–19) and jeopardized the survival of every independent community in Europe and beyond (Walzer 2015a: 252–4).
It is tempting to adduce biographical reasons for Walzer’s sense that Nazi brutality makes it the exceptional case that cannot be appeased. After all, as a Jewish boy born in 1935, he grew up in the shadow of the Holocaust. However, as a young Dissentnik from the mid-1950s onwards, Walzer has also always had a strong streak of anti-communism. Many of his early Dissent pieces criticized the post-Stalinist USSR or Maoist China (e.g. Walzer 1956, 1957, 1958b). This makes Walzer’s insistence that Soviet demands on Finland were not so exceptional as to require resistance somewhat surprising. But in this argument Walzer displays one of the