In The Stupidity of War, John Mueller engagingly and persuasively argues that the United States’ frequent use of force is unnecessary and frequently fails to achieve American aims (pp. 24–25). He reaches this conclusion largely through cases studies of US uses of force since World War II. Unlike advocates of retrenchment, however, Mueller supports continued US involvement in international institutions and alliances. Although he does argue for substantial cuts to US military spending, he believes the United States should remain diplomatically active in international affairs and open to occasional, small-scale uses of force. Thus, the argument is neither isolationist nor pacifistic in nature but instead is a compelling case against large-scale military adventures (pp. 193–96). Unsurprisingly given the overlap between his book and my own, I very much agree with his central conclusions.

Mueller bases these conclusions on three sub-arguments. First, he notes the steep decline in interstate war, which he attributes to global ideational shifts in beliefs about its utility (pp. 1–25). He argues that this decline undermines international relations theories, such as realism, which are based on an assumption of significant international security threats.

Second, Mueller soundly argues that this lower threat environment means states have time to respond to threats. They do not need to keep large militaries under arms and can often respond to the actions of rival states with complacency and even appeasement. Essentially, Mueller argues for a policy of careful patience in which force is rarely used (p. 16). Further, he argues that a smaller US military would help tame American military adventurism, because the United States could not engage in foolish wars if it lacked the ability to readily do so (pp. 197–99).

Last, despite the decline in interstate war and the concomitant increase in states’ safety, Mueller argues that the United States consistently inflates the level of threat it faces—both from other states, such as Russia, China, and Iran, and from armed nonstate groups like al-Qaeda. This is an argument he has long made, especially concerning terrorist threats. He argues that US policy makers focus on worst-case scenarios, base threat assessments on opponents’ intentions regardless of their capabilities, and indulge in overly heated rhetoric, thereby increasing the American public’s perception of danger (pp. 38–39, 121, 141). Moreover, he claims that minor powers, like Iran, cannot dominate regions such as the Middle East even if they acquire nuclear weapons, because great powers with vast nuclear arsenals have repeatedly failed at the same task (p. 109). Likewise, he asserts that aggressive moves by China in the South China Sea and by Russia in Ukraine, rather than strengthening those states, have simply pushed their neighbors toward the US diplomatic camp (p. 146–56). He defends these conclusions with compelling logic and evidence. In sum, Mueller’s arguments make a powerful case that the United States would be wise to use force far less often.

There are, however, two less convincing elements of Mueller’s argument: his dismissal of the historical importance of deterrence and of the United States’ role in maintaining the liberal international order. First, Mueller argues that the importance of deterrence in the post–World War II era has been vastly overstated and that it was not central to winning the Cold War. Specifically, Mueller claims the Soviet Union never intended to invade Western Europe and that the Marshall Plan was not needed to strengthen Western Europe against communist threats—internal or external (pp. 289). He rightly points out the Soviets were as concerned and cautious about initiating a general military conflict as the West was and were not planning to imminently invade Western Europe. Although accurate, these observations illustrate only that immediate deterrence was not needed and say nothing about the importance of general deterrence. The knowledge that NATO was sufficiently armed, both conventionally and with nuclear weapons, to defend against a Soviet assault or at least make such an attack prohibitively costly must have factored into the Soviets’ reluctance to contemplate such a war. Soviet intentions did not exist in a vacuum but were, in part, a function of Western capabilities.

In contrast, Mueller observes that the Soviets’ lack of a desire to attack could have resulted from communist ideology, which implied that historical processes would bring about revolution in capitalist states (p. 211). The Soviets, therefore, could afford to be patient. Even so, they undoubtedly desired to hasten the day of revolution. Soviet actions prior to 1948 support such a conclusion, and after World War II, the Red Army set up communist governments in the states it had occupied, as Mueller acknowledges. Further, the Soviets had previously used force to occupy eastern Poland, the Baltic states, and portions of Finland and Romania. The Red Army also intervened in the Mongolian Revolution in the 1920s. Finally, during the Polish-Soviet War of 1919–20, a period like 1945 of extreme war weariness (resulting from World War I and the Russian Civil War), the Soviets contemplated sending troops into Germany to foment revolution there. This plan was abandoned only after the Soviets were defeated outside of Warsaw (Norman Davies, White Eagle, Red Star, 1972). Thus, the Soviets were aggressive when conditions were favorable, suggesting deterrence was important for curbing Soviet ambitions during the Cold War.

This does not, however, undermine Mueller’s argument about American threat inflation during the Cold War. It is entirely possible for the Soviets to have posed a real threat and for the United States to have both overestimated the magnitude of that threat and falsely imagined that weak communist states in the developing world posed threats when they absolutely did not. One can face real dangers while simultaneously inflating their magnitude and conjuring additional, imaginary fears.

Second, Mueller underplays the importance of the United States in creating and maintaining the post–World War II liberal international order. His downplaying of the American role stems from his correct observation that US policy makers overemphasize American importance—for example, by calling the United States “indispensable.” He rightly argues that many other states—especially Western European states and Japan—share the American preference for a liberal order (pp. 213–14); those states played and continue to play vital roles in creating and maintaining that order. Similarly, Mueller is correct that nightmare scenarios, in which the global order totally collapses in the absence of US efforts, are fantastical despite being common in some policy circles (pp. 207–8). From these observations, Mueller concludes American actions were not necessary to the creation of this order. Strictly speaking this is accurate, because few social outcomes have truly necessary causes. Most outcomes are multicausal with many contributing factors, none of which is absolutely required. Certainly, one can envision other, less probable paths that the creation of the liberal international order could have followed.

However, US economic and security actions after World War II were, in practice, central to setting up the liberal order and have remained important in maintaining that order. Most notably, as Zacher argues, the territorial integrity norm—a key element of the international order in bringing about the decline of interstate war—was created and sustained in large part by US efforts (Mark Zacher, “The Territorial Integrity Norm,” International Organization, 55 [2], 2001). In addition, the United States would be a serious threat to the order if it sought to undermine it. Therefore, even if US actions are not necessary to the order’s existence, they still significantly increase the odds of its existence. Thus, Mueller’s useful corrective, that the United States is not in fact indispensable, goes too far and discounts the real American contributions to the current global order. Much as with deterrence, however, this does not undercut Mueller’s central point about the failures of American military force or that US foreign policy could benefit from greater complacency.

The US foreign policy implications of these two disagreements between Mueller’s call for a more peaceful foreign policy and my own are fairly small. On the main point we agree entirely: the need for an internationalist foreign policy focused on nonmilitary tools. We both favor the United States maintaining its alliances, behaving in ways consistent with the liberal international order, and abstaining from most active uses of force. The biggest policy difference is on military spending. Mueller advocates deep cuts, whereas I envision a reduced but important role for the US military in deterring attacks on US allies. Were that the main foreign policy debate in Washington, the United States would be in substantially different policy space than at present.

In short, Mueller has written a compelling and provocative book that challenges deeply held beliefs of many US policy makers and international relations theorists. Although Mueller’s arguments will not persuade everyone, they cannot easily be dismissed. They are well crafted and have significant implications for foreign policy and international relations theory. His book should be widely read by scholars and practitioners alike.