二次世界大戰資料庫 (WW2DB)

Contributor: David Stubblebine

Beginning in the late 1800s, the United States Army and the United States Navy developed a series of war plans for the purposes of preparedness and training. These plans pitted the United States against various adversary nations under hypothetical circumstances. At first, Army and Navy planners acted independently and so a Joint Army and Navy Board was created to reconcile any conflicts (this group is a direct predecessor of the Joint Chiefs of Staff). In 1904, the Army-Navy Board developed a system where major countries of the world were identified by colors and the remaining nations were given standardized abbreviations. Initially those colors were:

Following these assignments, war plans with the prospective nations started being called according to their color code. Most famously at the time was War Plan Black. Initially conceived during World War I and refined in 1919, War Plan Black addressed the possibility of France falling to Germany and the potential seizure of French possessions in the western hemisphere. War Plan Blue always involved defensive measures for the United States.

Throughout the 1920s and 1930s, the planning system evolved and some of the colors were reassigned. At certain times, one war plan or another would become the basis for Army exercises or the Navy's annual fleet problems. One Navy exercise in 1938 was based on War Plan Orange and included testing Hawaiian defenses in repelling a carrier-based air attack on the Hawaiian Islands. 1939 was the last year war plans used this scheme and it was replaced with the similar but distinct Rainbow War Plan system. There is some disagreement among the sources, but by 1939 the war planning colors had at various times included:

Notably absent are the Soviet Union and Italy (plans for Italy by this time presumably having been rolled into Plan Black).

Over the years, War Plan Orange received the most attention, revisions, and updates. Portions of it were followed reasonably closely during the Pacific War and it was an early version of Plan Orange where the idea of interning Japanese-Americans was put in writing for the first time.

War Plan White generally presumed American communists would pose the greatest internal threat.