LAUSR

What explains a state's decision to intervene in ongoing interstate conflicts? Intervention is a risky proposition, potentially incurring audience costs if the effort is unsuccessful or if casualties and other costs mount. Various domestic political factors and features of the international environment certainly shape the risks surrounding intervention, but recent work in political psychology suggests that individual leaders’ risk-taking propensity, as measured by their locus of control (LOC), greatly influences their willingness to engage in potentially risky actions. In this paper, we examine the link between US presidents’ risk propensity and the frequency with which they intervene internationally. Our analysis of the period 1946–2001 reveals that presidents with an internal LOC are generally more likely to intervene in ongoing conflicts. Moreover, such leaders are specifically more likely to engage in unilateral interventions and those geared toward harming the interests of interstate rivals, indicating a particular predilection toward risk-taking in their decision-making surrounding interventions.