The development of plans to protect the United States and the rest of the Western Hemisphere that concentrates on policy in the three years before Pearl Harbor, the gradual merger of hemisphere defense into a broader national defense policy, the transition to offensive plans after Pearl Harbor, and the military relationships of the United States with other American nations.

The development of plans to protect the United States and the rest of the Western Hemisphere that concentrates on policy in the three years before Pearl Harbor, the gradual merger of hemisphere defense into a broader national defense policy, the transition to offensive plans after Pearl Harbor, and the military relationships of the United States with other American nations.