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 problem of hemisphere defense -- The crisis of 1940 -- The Axis threat -- The American response : military policies and plans, 1940-1941 -- The Atlantic crisis of 1941 -- From nonbelligerency to war -- The shift toward the offensive -- General military relations with Latin America -- The supply of arms to Latin America -- Air defense preparations in Latin America -- Military relations with Brazil before Pearl Harbor -- The establishment of United States Army forces in Brazil -- The United States and Mexico : solidarity and security -- The United States and Canada : copartners in defense -- The United States and Canada : elements of wartime collaboration.