U.S. War Plan Orange

US-War-Plan-OrangeWar Plan Orange was part of a series of color-coordinated contingency plans. War Plan Orange was specifically outlined by the United States in preparation for fighting a war against Japan alone. Though this plan was first outlined in 1919, it actually served as a template that the United States forces would use during World War II.

Plan Orange formed the foundation for the actual campaign against Japan in World War II and included a pre-war economic blockade of Japan that the U.S. imposed and the plans for interning the Japanese-American population living in the mainland U.S.


Before the U.S. Color Coded War Plans

Early on in our history, the U.S. had prepared plans to deal with a plethora of potential global adversaries. The early war planning agencies were the U.S. Army Academy (West Point) and the U.S. Naval Academy as well. They served as some of the primary war colleges from 1890-1939. It was actually in 1903 that the Joint Army and Navy Board was created to help facilitate better arrangements for the two services working together, on a united front.

Initially, this board was given no independent authority in terms of planning and executing a war, but it did serve as the final review board for war plans that were submitted to it by the authorities from both the army and the navy.

It was after World War I that the Joint Board assembled its own official planning staff. From then on, the board actually had the power to initiate plans itself. The economic constraints that were placed on the military in the between-war eras forced the leaders of both the army and the navy to try to coordinate in ways that they had never done before, even more so than they had to during World War I. After the First World War, the Joint Army and Navy Board began to review all prewar plans to make sure that they were consistent with the world’s current state of affairs. This board was actually the precursor to what would later be established as the Joint Chiefs of Staff.


About US Color Coded War Plans

It was around 1904 that the US started to lay out extensive war plans for each and every country they considered that could potentially pose a threat in the near or distant future. They designed a system of colors and symbols that they used to identify each country, and the respective war plans that they would outline should a war break out between the United States and any of these other global powers. Whether this represented an invasion, uprising, intervention, or full-on war with another country, the US had developed a coordinated system and plans for every conceivable, and even largely inconceivable, war and combat scenarios.

Many of these war plans were created during the 1920s, after the First World War. Even though the United States’ military leaders believed that the majority of these scenarios for war would be extremely unlikely considering the state of global affairs at the time. Higher-ranking officers would use these plans as tools to keep more junior officers not only busier but on their toes as well. They would have them make regular updates to these respective plans for war as the state of affairs around the globe or our relationship with that country would change. This became a critical task for these officers to stay abreast of world affairs at all times, and became even more complicated as the color coordination system was changed over time. This resulted in the changing of certain countries’ colors, which made the system and map more confusing and harder to keep track of.


List of Color-Coded War Plans

The biggest, most elaborate, and most notable war plan was perhaps that of War Plan Black. This was the U.S.’s war plan that they had constructed should they again go to war with Germany. This was created by the board during World War I as a contingency plan in case France was overrun by the Germans, or if the Germans tried to seize the Caribbean, which at the time was under French possession. This plan also detailed a war response to the Germans if they were to attack the eastern seaboard of the United States.


Considerations for War Plan Orange

War Plan Orange was the plan that may have received the most thought and consideration form the United States. This specific plan detailed and coordinated the events following if the United States were to fight Japan on their own. War Plan Orange was outlined unofficially back in 1919. It was officially added to our potential war plans in 1924. What was even more interesting is that War Plan Orange was later used as a framework and reference for the actual campaign that the United States waged against Japan during World War II. It even went to the lengths of outlining the economic blockade that the US would set up from mainland China and the country’s plans for creating internment camps for the Japanese-American population.

Originally, this plan had anticipated a blockade of the Philippines and several other United State’s outposts that were located in the Western Pacific. It planned for those bases to hold out on their own, while the Pacific Fleet gathered their forces in California, preparing to defend against attacks on the Panama Canal. After the Pacific Fleet was mobilized, they would sail over to the Western Pacific to relieve the American troops in the Philippines and Guam. From there, the fleet would plan to sail north to do battle with the Imperial Japanese Navy’s Combined Fleet. After a successful siege, the Pacific Fleet would then Blockade the home islands of Japan.

Japan expected this, however, and developed their own counter-plan to the United States in the event that the Pacific Fleet would mobilize and try to shut them down. This plan included deploying their subs to attack and chip away at the Pacific fleet as they traveled across the Pacific Ocean. After weakening the Pacific Fleet, Japan planned to force a strategic naval battle in their territory.

One of the main reasons that Japan posed such a considerable threat to the United States was that they capitalized on certain opportunities that presented themselves during the First World War. Namely, that they were able to take a strategic military foothold in the Pacific Ocean. Though this could have posed a serious concern to the United States, this fear was put to ease when the Japanese government decided to temporarily halt their program for military expansion.


Multilateral War Plans

One of the other most detailed war plans that the U.S. made during this time was their Red-Orange plan. This outlined if the United States came to war with the Anglo-Japanese Alliance, which came to an end in 1924.

This was the plan that was the most detailed due to the fact that it was the one that concerned the United States forces and military leaders the most. The reason that this was one of the utmost concerns and contingency plans for the United States is that this would demand that they fight a naval war over two oceans between Japan and Britain. Fighting a naval battle on two fronts would have spread the United State’s navy thin, and threatened the war becoming domestic, on U.S. turf.


Actual Events Between the United States and Japan

More or less, the actual events outlined in both the Japanese and the United States plans took place. Though, there were some unexpected events and occurrences on both sides. In the carrier battles, the use of airplanes and submarines far outweighed the action that happened on the surface. The Japanese Navy had expected to be on the attack against the Pacific Fleet, they didn’t plan for defending themselves against American submarines. Therefore, Japan failed to run an effective counter-strategy to the United State’s fleet of submarines. The American subs ended up playing a critical role in paralyzing Japan’s navy along with choking their industrial product and economy.



Though the actual events that transpired during World War II were slightly different from those that were outlined in War Plan Orange, this plan served as an effective military outline for how the US would respond in the face of a threat from Japan. Detailed careful planning like this is what inevitably led to the successes of the United States army and navy during the war.