The Influence of Domestic and International Politics on the President's Use of Force

Ostrom and Job (1986) found that domestic, political factors are more influential on the president's decision to use military force than characteristics of the international environment. These results pose a serious challenge to realists' assumptions regarding the motives of states and the separability of domestic and foreign policy. This article reexamines Ostrom and Job's arguments and introduces a new indicator, a measure of the severity of ongoing international crises, to provide a better assessment of the relative effect of the international environment on presidential decision making. This severity index is significantly associated with the use of force by the United States from 1949 through 1976, and proves to be more influential than the international indicators used by Ostrom and Job. Nevertheless, domestic political factors remain most consequential in the president's decision to use force short of war.