Realist theories of international relations tell us that the security behavior of great powers is motivated by uncertainty about the willingness and ability of other states—now or in the future—to threaten their continued survival. Uncertainty in this telling is not a social, psychological, or political phenomenon; rather it is an omnipresent background condition. But, as Ted Hopf once noted, states more often act of certainty rather than out of uncertainty: certainty of threat and certainty of response. Hopf's observation begs the question: how do states, their publics, and leaders respond in the face of uncertainty to transform it into certainty?

To answer that question, uncertainty must be situated as a social, psychological, and political phenomenon. Alexandra Homolar does just that in her excellent book The Uncertainty Doctrine. Homolar finds uncertainty as an experienced condition for theory and analysis in temporal disjuncture, when events in the world suggest international relations in the future will be configured differently than those of the past. A variety of scholars, including myself, have used the idea of disjuncture in one form or another to gain analytical leverage. What sets Homolar's treatment apart is the careful and theoretically rich engagement with disjuncture as an intersubjectively constructed experience. Wh