"War Plan Blue" is a war plan used in a time of peace

War Plan Blue[24]Covered defensive plans and preparations that the United States should take in times of peace. During the 1920s and 1930s, the United States military Joint Army and Navy Board developed a number of color-coded war plans to outline potential U.S. strategies for a variety of hypothetical war scenarios. The plans, developed by the Joint Planning Committee (which later became the Joint Chiefs of Staff), were officially withdrawn in 1939 in favor of five Rainbow Plans developed to meet the threat of a two-ocean war against multiple enemies.

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