Leaders often invoke reputations to justify war, but reputations are notoriously based on beliefs, not observable facts. To make things worse, both leaders and states may cultivate reputations that are irreconcilable. Finally, it is not always clear when commitments are interdependent or when today's choice is indicative of future choices. In her new book, political scientist Keren Yarhi-Milo[1] (Columbia Univ.) explores the reasons why some leaders are willing to expend blood and treasure to bolster their country's reputation when they believe they can, while others are not.

The author argues that leaders' concerns about their state's reputation are in part dispositional. Some leaders are predisposed to care more than others about the impression they make on international audiences, with resulting differences in their handling of crisis bargaining. High self-monitors (HSMs), disposed to control their behavior to influence others' beliefs, will fight to influence others' perceptions of their resolve and thereby accumulate social capital. By contrast, low self-monitors (LSMs), inherently averse to such performative behavior, focus more narrowly on the immediate costs and benefits of military action. As a stable personal trait with genetic roots (20–24), self-monitoring can be an observable independent cause of political behavior.

The distinction between high and low self-monitors is sharpest among doves, that is, leaders generally hesitant to use military force, but whose desire to preserve a reputation for resolve can induce them to fight. Even among hawkish leaders willing to fight over a wider range of issues, self-monitoring shapes just how they justify the fights they pick.

After chapters 1 and 2 establish the puzzle and cover the theory, chapters 3–8 marshal a wealth of statistical evidence to support the book's key claims. Survey experiments in the United States and Israel show that high levels of self-monitoring among individual respondents predict a willingness to support war over ostensibly non-vital security interests.[2] Statistical models have linked the onset of international conflict and self-monitoring scores for Cold War-era American presidents.[3]

Chapters 6–8 examine the crisis behaviors of presidents Jimmy Carter, Ronald Reagan, and Bill Clinton. Carter, a dovish LSM, was reluctant to fight for reputation even as his advisors pressed him to address superpower crises in Africa; but he took immediate action when Soviet troops invaded Afghanistan in 1979. Reagan, a hawkish HSM, justified interventions in Grenada and Libya, escalation in Afghanistan, and slow withdrawal from Lebanon in starkly reputational terms. And Clinton, a dovish HSM, invoked the preservation of American credibility to justify a surge in Somalia after the Battle of Mogadishu, intervention in Haiti to restore the elected president, and deterrent moves in the Taiwan Strait after Chinese missile tests.

Yarhi-Milo hints at tantalizing links to other theoretical work. Game-theoretic studies, for example, have disclosed evidence of the value of reputations in international relations. But, while game models can explain much about how individual dispositions (say, for hawkishness) influence reputational dynamics, they have little to say about the preferences and strategies that predispose leaders to fight for reputation, which may stem from, as Yarhi-Milo shows convincingly, psychological predispositions. Rather than asking whether and/or which commitments are interdependent, future research may identify which sorts of leaders are likely to see commitments as interdependent and, hence, be apt to fight for reputation.

The author succeeds in connecting presidential dispositions with conflict behavior. In one instance, however—late-tenure fights to preserve face—she argues that "the length of a leader's tenure does not determine whether she is willing to fight for reputation" (268). Theories that predict greater early-tenure concerns over reputation are necessarily probabilistic, which means that one cannot infer the absence of such a pattern based on her small sample. In fact, time in office appears unrelated to overall conflict rates but negatively tied to rates of conflict initiation (90, 98). If one accepts dispute initiation as signifying a willingness to fight for face—a claim in line with other research—then the book would seem to present evidence consistent with tenure-related predictions. But this inference does not undercut the convincing evidence that self-monitoring is related to a given leader's willingness to bear the costs and risks of conflict in order to shape the beliefs of international audiences.

A book on presidential personalities and the use of military force will inevitably be read in light of the Donald Trump presidency. And, indeed, Yarhi-Milo's efforts point to the right questions to ask about a singular moment in American history. Is Trump a high self-monitor? He certainly cares about his image, but does he, like most HSMs, care mainly about international rather than domestic audiences in crises because they confer social capital and standing (26)? Or does Trump value social standing only within the world of his domestic political base? If so, then what message does his public posturing, threatening, and strenuous handshaking for domestic consumption convey to other states regarding his foreign policies, in particular the risks of escalation and the ability to climb down the ladder of escalation?

Yarhi-Milo offers her readers a useful framework for analyzing both the often-puzzling Trump presidency and those that preceded it. Policymakers, students, and scholars alike will value the insights that Who Fights for Reputation provides into past, present, and future American foreign policy.