Why do nations go to war? The study of war in both national and temporal contexts occurs at the intersection of two important scholarly concerns. The first is the broader question of how geography is a component of world politics. The second is the question of how to model political processes that vary both across nations and across time. Little research has capitalized on recent advances in statistical modeling of spatial processes developed by statisticians. Ward, Heagerty, and Gleditsch will analyze data on all international conflicts since 1800 and on the type of governing institutions in each country during this period. They will use novel statistical methods to model temporal context.