Uncertainty is an ever-present and ineradicable aspect of politics. It affects all important issues of governance and policy, in both domestic and international contexts. Rather than treating the uncertainty of politics as a mystery, this book provides an original and direct treatment of political uncertainty as a scientifically-knowable phenomenon with well-defined principles and substantive properties. Specific applications of this theory of political uncertainty are demonstrated in diverse areas of politics, examining such questions as when and how wars break out, when and how governments collapse, and when and how political cooperation emerges. The author shows how probability and mathematical modeling can play a central role in understanding such complex and fundamental issues.