Current discussions of war take their primary cue from the catastrophic history of war in the twentieth century. Not only is the claim about the twentieth century as being the most murderous in recorded human history widespread. Equally pervasive are reflections about the senseless nature of most of its carnages. Both views found ample resonance at the close of the past century as discourses of human rights, humanitarianism, and doctrines such as “the responsibility to protect” became emblematic. And a corollary to these discussions has been the reemergence of the idea of “just war” theory: for every discussion of war is also a discussion about predicaments of life and death that involves considerations of violence, proportionality, and power.

In predicaments of war, what is often at stake are not only individual deaths but also the death of political entities and collective identities. Historically, these questions have found prescient treatment in the interstices of imperial domains. From Augustine to Las Casas, Vitoria, Grotius, and Vattel, the demands, imperatives, and travails of imperial rule have served as the context for reflections on the justice of war. In Justice, Intervention, and Force in International Relations, Kimberly A. Hudson fails to critically register these imperial contexts, even if her discussion of just war theory and her reworking of Michael Walzer's influential account unwittingly attests to it: Walzer's reflections are situated within the tumultuous times of American imperium and its misadventures in Vietnam. Likewise, it is a settler colonial society—namely, Israel—that serves as his archetype to justify a war of preemption. But aside from the occasional remark noticing the existence of empires in relation to some of the aforementioned thinkers and a rather cursory mention of Israel, Hudson's book does not consider these dilemmas. It is concerned, rather, with updating just war theory, which the author does by way of a sympathetic engagement with Walzer's Just and Unjust Wars: A Moral Argument with Historical Illustrations (1977). This is the strength of the book, even if it would have presented a more forceful argument had it considered some of the aforementioned questions.

Hudson's argument is straightforward: Her book sets out to develop Walzer's account of just war theory. As such, it is an apt summary of his positions and a sympathetic account of his critics and Walzer's rejoinders to them. It provides a good account of his positions and their evolution, from the time he first penned Just and Unjust Wars, to the modifications offered in subsequent prefaces and in his engagements with critics, to his most recent forays in the international arena in the contexts of Kosovo and the current war in Iraq. Hudson ably recounts the objections of some critics to Walzer's restriction of offensive wars and painstakingly reconstructs these arguments and his responses to them, which she ultimately finds unsatisfactory.

The aim of this book goes beyond offering an account of Walzer and his critics, however. Hudson seeks to update his account by way of a sympathetic if sharp criticism of his doctrine. As she writes at the outset: “Although I am explicitly critical of several of Walzer's arguments, this project is written in the spirit of engaging and supplementing Walzer's work, not in the spirit of demolition” (p. 1). Hudson certainly lives up to the promise of her critique since she does move beyond her subject in significant ways. This book could thus be read as an update of just war theory that, while taking Walzer as its main signpost, seeks to formulate a theory of just war akin to the demands of an age in which new norms—such as “sovereignty as responsibility,” “responsibility to protect,” and “responsibility to prevent”—have emerged.

What does this update of Walzer's positions look like? The general contours of his arguments are well known: In Hudson's rendering, while defensive wars can be justified as just, with the exception of societies engaged in genocide, enslavement, and ethnic cleansing, offensive wars are deemed to be always unjust. The latter constitute crimes of aggression that no just war theory could redeem. Of course, Walzer did leave space for “pre-emptive wars” of self-defense. Israel's Six Day War provides the archetype for them. But aside from these instances, he restricted the scope for justifying offensive wars. Indeed, as Hudson observes, “Walzer's discussion of pre-emption in Just and Unjust Wars does not include any mention of pre-emptive collective self-defense or pre-emptive humanitarian intervention” (p. 11). Even so, there is something odd in this charge, for humanitarianism did not go to war until much later; thus, to chide Walzer for not considering a doctrine that had no valence at the time he worked out his reflections is not historically sound. Rather than a limitation in his account, what that charge attests to is the lack of attention to historical and geopolitical contexts in Hudson's book, which is what ultimately mars her efforts.

Hudson, in contrast to Walzer's position, wants a more expansive theory of just war that can make room for these forms of preemption. She claims that his norm of nonintervention rests on “unstable grounds” and seeks to provide “more stable grounds” by way of the contemporary doctrines, such as the responsibility to protect and sovereignty as responsibility. In other words, she aims at a more expansive threshold of legitimacy for offensive just wars that is more in sync “with the complexity of contemporary international relations” (p. 159). Hudson's more “comprehensive framework,” she claims, is at once more permissive in its scope, but it also offers clearer criteria of restraint.

Yet when it comes to putting the argument to work, there is an unreflective moralism that betrays the righteousness one associates with the catacombs of power. Hudson thus uses adjectives such as “indecent,” “irresponsible,” and “wicked” to refer to states of which she disapproves—a language, to be sure, that is part and parcel of the post–September 11, 2001, new nomos of the earth that this book, perhaps unwittingly, exemplifies. The conclusions reveal the book's intended audience, as well as a certain naïveté in relation to imperial might: “Prevention is always less costly than fighting. Because the just case criteria have been expanded in the Atrocity Standard, outsiders have a right of interference in matters that under the old paradigm were considered to be matters of internal concern. The practical significance of these changes is that outsiders are permitted to interfere earlier. Earlier translates to more proportionately, especially if armed conflict is to be avoided altogether by preventive diplomatic, economic, social, or military means” (p. 162). That the Atrocity Standard often involves a slippage from the responsibility to protect to the “right to punish,” in Mamhood Mamdani's powerful rendering, is nowhere considered in this book. But with the communist enemy off the field, a new lease on life was given to ideologies of U.S. imperialism. And that is the context for the Western salience of the responsibility to protect and its almost simultaneous slide to a doctrine that effectively portends the right to punish.

At the end of the Cold War, as enmity lines began to be redrawn and the onset of a new international settlement was about to be structured with the United States as the sole superpower, a new nomos of the earth was crystallized. Herein a convergence of the so-called process of globalization, neoliberalism, and the increasing frustration of humanitarian workers and advocates that led them to embrace war as a means for achieving their humanitarian ends—which was conjoined with the reemergence of Western developmentalist discourses in the context of an ethical turn in political and critical theory—leading to the deployment of the same moralist rhetoric at work in Hudson's book to authorize wars of preemption set the precedent for the ill-conceived invasion and recolonization of Iraq. And herein is where the slide and slippage from “responsibility to protect” to “the right to punish” has taken hold of the North Atlantic imagination.

Within this context, concrete justice is perhaps better served by reining in imperial might and its pieties about just wars, humanitarianism, and rights. Ironically, one would think that reckoning with the present times would lead advocates of just war theory to establish more restrictive criteria to counter the increasing vacuity of this rhetoric due to the crass instrumentalizations of it in the last two decades. But then, again, ideologies of just war theory have often been the conceit of empires. Insofar as Hudson's account fails to critically register the restructuring of the political field and its ideological conceits, or to self-reflectively engage with the imperial lineages of this doctrine, a fitting characterization of her book's aim is to see it as a defense of unjust war in the twenty-first century.