The observation that groups unify in the face of common threats is long-standing. At the level of the nation-state, this is called the “rally-'round-the-flag” phenomenon. In the case of the United States, the rally phenomenon is measured as a surge of public approval for the president when the nation is involved in an international crisis. Two hypotheses have been offered for why this surge of support occurs: (1) patriotism, as individuals respond to a threat by identifying with an in-group, in this case the nation and its president; and (2) opinion leadership, as the information environment changes because opposition leaders fall silent or support the president during a crisis and a portion of the public follows those elite partisan cues. Through three waves of scholarship, empirical evidence has cumulated about whether, when, why, and how much people rally in response to international crises (although much of the evidence is based on dynamics within the United States). The public’s reaction to a crisis is not automatic; sometimes public approval for the president goes up; other times the president’s approval ratings go down. A positive rally effect is associated with a variety of conditions, such as how prominently the event is reported, whether the White House actively frames the issue, the amount of criticism from opposition elites, and whether the country is at war or has recently concluded a war. The sizes of such rallies are variable, but on average, rallies in response to the deployment of force or international crises are small. Only wars (or other spectacular events like a large-scale terrorist attack) consistently provoke sizable rallies and these big events elicit an emotional reaction from citizens and a self-identification with the nation. Both hypotheses—patriotism and opinion leadership—are helpful in explaining why rallies occur and why they taper off over time. The “diversionary theory of war” or the “diversionary use of force” is, for obvious reasons, a companion literature to the scholarship on rally effects. The logic is simple: if the public rallies around its leader in the face of external threats, then the possibility exists that politicians will intentionally create crises or deploy military forces or start wars to enhance their own political fortunes. Scholars have spent much effort trying to locate patterns of diversionary behavior by American presidents and other world leaders with inconsistent and inconclusive results. But the cumulative findings from the rally-'round-the-flag scholarship show that leaders can’t expect much of a public rally from any but the most spectacular of international crises, such as full-scale war. These findings from the rally literature help to explain the lack of consistent empirical support for diversionary theory.
Benjamin O. Fordham
In the three decades since Jack Levy published his seminal review essay on the topic, there has been a great deal of quantitative research on the proposition that state leaders can use international conflict to enhance their political prospects at home. The findings of this work are frequently described as “mixed” or “inconsistent.” This characterization is superficially correct, but it is also misleading in some important respects. Focusing on two of Levy’s most important concerns about previous research, there has been substantial progress in our understanding of this phenomenon. First, as Levy suggests in his essay, researchers have elaborated a range of different mechanisms linking domestic political trouble with international conflict rather than a single diversionary argument. Processes creating diversionary incentives bear a family resemblance to one another but can have different behavioral implications. Four of them are (1) in-group/out-group dynamics, (2) agenda setting, (3) leader efforts to demonstrate competence in foreign policy, and (4) efforts to blame foreign leaders or perhaps domestic minorities for problems. In addition, researchers have identified some countervailing mechanisms that may inhibit state leaders’ ability to pursue diversionary strategies, the most important of which is the possibility that potential targets may strategically avoid conflict with leaders likely to behave aggressively. Second, research has identified scope conditions that limit the applicability of diversionary arguments, another of Levy’s concerns about the research he reviewed. Above all, diversionary uses of military force (though not other diversionary strategies) may be possible for only a narrow range of states. Though very powerful states may pursue such a strategy against a wide range of targets, the leaders of less powerful states may have this option only during fairly serious episodes of interstate hostility, such as rivalries and territorial disputes. A substantial amount of research has focused exclusively on the United States, a country that clearly has the capacity to pursue this strategy. While the findings of this work cannot be generalized to many other states, they have revealed some important nuances in the processes that create diversionary incentives. The extent to which these incentives hinge on highly specific political and institutional characteristics point to the difficulty of applying realistic diversionary arguments to a large sample of states. Research on smaller, more homogenous samples or individual states is more promising, even though it will not produce an answer to the broad question of how prevalent diversionary behavior is. As with many broad questions about political phenomena, the only correct answer may be “it depends.” Diversionary foreign policy happens, but not in the same way in every instance and not in every state in the international system.