United States color-coded war plans


During the 1920s and 1930s, the United States military Joint Army and Navy Board developed a number of color-coded war plans that outlined potential U.S. strategies for a variety of hypothetical war scenarios. The plans, developed by the Joint Planning Committee, were officially withdrawn in 1939 in favor of five Rainbow Plans developed to meet the threat of a two-ocean war against multiple enemies.

Colors

The use of colors for U.S. war planning originated from the desire for the Army and Navy to use the same symbols for their plans. At the end of 1904, the Joint Board adopted a system of colors, symbols, and abbreviated names to represent countries. Many war plans became known by the color of the country to which they were related, a convention that lasted through World War II. As the convention of using colors took root, some were eventually reused, such as Grey, which originally referred to Italy but eventually became a plan for the capture and occupation of Portugal’s Azores.
In all the plans the U.S. referred to itself as "Blue".
The plan that received the most consideration was War Plan Orange, a series of contingency plans for fighting a war with Japan alone, outlined unofficially in 1919 and officially in 1924. Orange formed some of the basis for the actual campaign against Japan in World War II and included the huge economic blockade from mainland China and the plans for interning the Japanese-American population.
War Plan Red was a plan for war against Britain and Canada. British territories had war plans of different shades of red—the UK was "Red", Canada "Crimson", India "Ruby", Australia "Scarlet" and New Zealand "Garnet". Ireland, at the time a free state within the British Empire, was named "Emerald". The plan was kept updated as late as the 1930s and caused a stir in American–Canadian relations when declassified in 1974.
War Plan Black was a plan for war with Germany. The best-known version of Black was conceived as a contingency plan during World War I in case France fell and the Germans attempted to seize French possessions in the Caribbean or launch an attack on the eastern seaboard.

Considerations

Many of the war plans were extremely unlikely given the state of international relations in the 1920s, and were entirely in keeping with the military planning of other nation-states. Often, junior military officers were given the task of updating each plan to keep them trained and busy. Some of the war plan colors were revised over time, possibly resulting in confusion.
Although the US had fought its most recent war against Germany and would fight another within twenty years, intense domestic pressure emerged for the Army to halt when it became known that the Army was constructing a plan for a war with Germany; isolationists opposed any consideration of involvement in a future European conflict. This may have encouraged the Army to focus on more speculative scenarios for planning exercises.

The Americas

War Plan Green

During the 1910s, relations between Mexico and the United States were often volatile. In 1912, U.S. President William Howard Taft considered sending an expeditionary force to protect foreign-owned property from damage during the Mexican Revolution. Thus War Plan Green was developed. In 1916, U.S. troops under General John Pershing invaded Mexico in search of Pancho Villa, whose army had attacked Columbus, New Mexico; earlier, American naval forces had bombarded and seized the Mexican port of Veracruz, and forced Victoriano Huerta to resign the presidency. In 1917, British intelligence intercepted a telegram from the German foreign ministry to its embassy in Mexico City offering an alliance against the United States and assistance in the Mexican reconquest of the Southwest. Released to American newspapers, the Zimmermann Telegram helped turn American opinion against Germany and further poisoned the atmosphere between the USA and Mexico. Relations with Mexico remained tense into the 1920s and 1930s.

Beyond Mexico

Additionally, between the American Civil War and World War I, the American military intervened in the affairs of Latin American countries, including Colombia/Panama, Haiti, Cuba, and Nicaragua. In doing so, parts of "Gray" and "Purple", plans were considered although never officially activated.

Multilateral war plans

Some plans were expanded to include war against a coalition of hostile powers.
The most detailed was Red-Orange, based on a two-front war against the Anglo–Japanese Alliance, which expired in 1924. This was the contingency which most worried U.S. war planners, since it entailed a two-ocean war against major naval powers. Theories developed in wargaming Red-Orange were useful during World War II, when the United States engaged the Axis in both the Atlantic and Pacific simultaneously.

Rainbow plans

had used the opportunity afforded by World War I to establish itself as a major power and a strategic rival in the Pacific Ocean. After the war, most American officials and planners considered a war with Japan to be highly likely. The fear lessened when the civilian government of Japan temporarily halted their program of military expansion, which was not to resume until 1931. War Plan Orange was the longest and most-detailed of the colored plans.
However, following the events in Europe in 1938 and 1939, American war planners realized that the United States faced the possibility of war on multiple fronts against a coalition of enemies. Therefore, the Joint Planning Board developed a new series of war plans, the "Rainbow" plans—the term being a play on the multiple "color" plans that had been drawn up previously.

  • Rainbow 1 was a plan for a defensive war to protect the United States and the Western Hemisphere north of 10th parallel south|ten degrees latitude. In such a war, the United States was assumed to be without major allies.
  • Rainbow 2 was identical to Rainbow 1, except for assuming that the United States would be allied with France and the United Kingdom.
  • Rainbow 3 was a repetition of the Orange plan, with the provision that the hemisphere defense would first be secured, as provided in Rainbow 1.
  • Rainbow 4 was based on the same assumptions as Rainbow 1, but extended the American mission to include defense of the entire Western hemisphere.
  • Rainbow 5, destined to be the basis for American strategy in World War II, assumed that the United States was allied with Britain and France and provided for offensive operations by American forces in Europe, Africa, or both.
The assumptions and plans for Rainbow 5 were discussed extensively in the Plan Dog memo, which concluded ultimately that the United States would adhere to a Europe first strategy in World War II.
Plans for Rainbow Five were published by the press in early December 1941.

List of color plans

According to the public intelligence site, Global Security, the following plans are known to have existed:
; War Plan Black
; War Plan Gray
; War Plan Brown
; War Plan Tan
; War Plan Red
; War Plan Orange
; War Plan Red-Orange
; War Plan Yellow
; War Plan Gold
; War Plan Green
; War Plan Indigo
; War Plan Purple
; War Plan Violet
; War Plan White
; War Plan Blue