The Cost of War

How Many Casualties Will Americans Tolerate?

Misdiagnosis

CHRISTOPHER GELPI

In "The Iraq Syndrome" (November/December 2005), John Mueller argues that public support for the American wars in Korea, Vietnam, and Iraq can be explained with "a simple association: as casualties mount, support decreases." He goes on to say that support for the Iraq war has dropped so fast that it makes sense to talk about an "Iraq syndrome," a casualty-induced aversion to the future use of force by the United States.

Mueller's landmark contributions to the study of public opinion and war have rightly earned him much respect and inspired a large portion of the scholarly agenda taken up by me and my research partner, Peter Feaver. In this essay, however, he is only partially correct. The public is, as he notes, sensitive to casualties: casualties are the cost of war, and the public would prefer the same outcome (victory) at lower cost (fewer casualties). But when he steps from there to casualty-phobia -- a sensitivity to casualties so acute that it paralyzes policymakers -- Mueller goes far beyond his limited data and must ignore extensive evidence that runs counter to his theory. Even the limited data Mueller cites disprove his own central claim: that support drops steadily and inexorably with mounting casualties regardless of context. Along the way, Mueller grossly misstates the findings from my co-authored research and largely overlooks research by Richard Eichenberg, Bruce Jentleson, Steven Kull, Eric Larson, and others that adds more nuance to this picture.

MODERN SENSITIVITIES

Casualty sensitivity may be thought of as price sensitivity to the human cost of war. As with other forms of price sensitivity, some members of the public are more sensitive to casualties than others, and one person's sensitivity to casualties may vary over time.

In fact, the public's willingness to bear the human cost of war has varied substantially during different phases of the wars in Korea, Vietnam, and Iraq. The key variable is the perceived likelihood that the mission will succeed. Variations in perceptions of success over time have substantially altered the extent to which casualties have eroded aggregate public support for each war. Varying perceptions of success have also played a major role in determining which individuals have decided to oppose the war in Iraq, specifically, and when. It is this breadth of evidence that led me and my co-author to characterize the American public as "defeat-phobic" rather than "casualty-phobic."

Mueller cursorily dismisses our research by citing out of context a survey statistic we report in a 1999 op-ed: the mean response to a question about the number of acceptable casualties in a hypothetical U.S. military intervention in the Democratic Republic of the Congo. Mueller clings to a confused reading of that statistic, despite our extensive discussion in a subsequent book, Choosing Your Battles. We invite readers to read pages 95-148 to decide for themselves whether Mueller has accurately reported our argument. For the record, our interpretation of the (limited) survey results we discuss in that book is that a majority of the American public claims it would tolerate something on the order of a hundred casualties to bring democracy to Congo. Our main point, however, is that the focus of policymakers and pundits on casualties, without reference to context, is misguided, because public support for a military operation will erode sharply in the face of mounting casualties when the public believes the war is failing but will remain relatively robust when the public believes the war is succeeding. This argument is based on extensive analyses of scores of surveys -- including much of the survey data on which Mueller relies.

Mueller's claim that public support for the Korean War dropped as casualties mounted, for example, does not withstand scrutiny. The assertion of such a relationship is based entirely on a single observation: the drop in public support between August and December 1950. Mueller attributes this drop to the 10,000 U.S. battle deaths during this period, but he fails to note that the United States was also suffering some of its most lopsided battlefield defeats at the time, as Chinese forces swept down the peninsula. Furthermore, he fails to note that public support for the war increased by eight percentage points between December 1950 and August 1951 despite the fact that nearly 8,000 American soldiers were killed during that period. Why did public support rally despite the mounting casualties? Because U.S. forces managed to recapture South Korean territory and stabilize the front at the 38th parallel. Public support only began to wane again when casualties mounted -- though not precipitously -- after the war settled into a stalemate.