Foreign Overt Military Intervention in the Nuclear Age

Competing theories about who is most responsible for the overall frequency and geographic scope of international armed conflict in the nuclear age are systematically tested against the record of states' warlike actions since World War II. These theories include the traditional view of `power politics' which assumes that intervention is practiced primarily by great powers and the vision of `nuclear paralysis' which presumes that great powers use military force infrequently compared to aggressive minor states. The frequency of foreign overt military intervention both within and outside of war is compared among all states. Analysis is based upon a new catalog of international armed conflicts, the OVERT MILITARY INTERVENTION file, that attempts to identify all foreign overt military interventions initiated since World War II. Ninety-seven states initiated 591 foreign overt military interventions within 269 international armed conflicts between 1945 and 1985. All international armed conflicts, the intervenors and their territorial targets are named in an Appendix that accompanies the article. Results provide partial support for both the power politics and nuclear paralysis perspectives but also raise questions about the adequacy of each of these views. Great powers excepting the Soviet Union have intervened more frequently than have virtually all other states, and the Soviet Union is not far behind. China, France and the United Kingdom, however, now intervene less frequently than they did in the first decades after World War II. Moreover, great powers as a group account for only a small fraction of all foreign overt military interventions, in part because nearly all but very small states intervene occasionally. Direct responsibility for the incidence and scope of contemporary international armed conflict is more diffuse than is implied by some traditional theories of power politics. At the same time, great powers employ warlike force more often than is implied by the image of nuclear paralysis.