The Problem of Shared Victory: War-Winning Coalitions and Postwar Peace

War-winning coalitions face a unique problem of ensuring multilaterally credible commitments to the distribution and defense of a new postwar status quo. Some sustain cooperation for years or decades, yet others collapse into intramural violence. Why do some victorious coalitions collapse into war, while others do not? I analyze data on war-winning coalitions from 1816 to 2007, using an event history framework to model the duration of postwar peace between their members. Increasing coalition size is associated with less durable postwar peace, while more extensive prewar alliance commitments are associated with less durable peace and great power participation is associated with more durable peace. These results have implications for the survival of postwar settlements, for the role of alliances and great powers in preserving world order, and for assessing the implications of modern theories of war.