From the Summary: "This report reviews the historical record regarding the uses of U.S. military force in a 'preemptive' manner, an issue that has emerged due to the possible use of U.S. military force against Iraq. It examines and comments on military actions taken by the United States that could be reasonably interpreted as 'preemptive' in nature. For purposes of this analysis we consider a 'preemptive' use of military force to be the taking of military action by the United States against another nation so as to prevent or mitigate a presumed 'military' attack or use of force by that nation against the United States. This review includes all noteworthy uses of military force by the United States since the establishment of the Republic."
CRS Report for Congress, RS21311