Following World War I, the United States and the Empire of Japan competed for power and prestige in Southeast Asia. Both nations had secured islands from the defeated German Empire in the South Pacific and had established interests elsewhere in Asia, such as the Japanese occupation of Korea and Manchuria and the American presence in the Philippines. As their ambitions grew, the nations steadily headed on a collision course that resulted in them fighting in World War II when the Japanese launched an attack on Pearl Harbor on December 7, 1941.
Two key factors that led to war in the Pacific were Japanese expansion in China and the subsequent American embargo on Japan. With tensions mounting, the American government, under President Franklin D. Roosevelt, directed the FBI to research the interests and activities of potential foes, namely the Japanese Empire and Nazi Germany. The bureau produced an atlas in 1935 titled “Japanese Pre-War Colonization”. The work displays four Japanese-language maps that are accompanied by maps that translate the content into English.
Perhaps the most important map in the atlas concerns the Japanese presence in Southeast Asia. The map depicts locations and numbers of Japanese nationals, as well as Japanese commercial interests, consulates, resources and shipping routes.
By 1935, some 36,134 Japanese lived throughout Southeast Asia, and of them, some 21,468 lived in the Philippines and were in engaged in the lumber and fishing industries. On the Indonesian island of Celebes, today known as Sulawesi, the Japanese owned and operated the Borneo Petroleum Co. Elsewhere, Japanese firms mined iron and manganese. Access to these resources was critical to the Japanese economy and military, as Japan has few natural resources of its own.
Commerce in Southeast Asia was critical to Japan. The empire was furiously importing rubber, hemp, diamonds, gold, tin, coal, and petroleum from throughout the region. It was also importing silk, cotton, pepper, salt, rice, sugar, tobacco, fish and other goods. Japanese shipping companies had developed a network between islands in the Southeast Pacific and Japan.
Before the start of World War II, more than a million Japanese were living abroad. Among them, some 112,418 lived in the United States. The FBI was concerned that among them were potential spies and saboteurs. The belief was rooted in the American experience during World War I when the Germans either dispatched spies and saboteurs to the United States or recruited German nationals or German-Americans for such clandestine operations.
The full extent to which these maps were directly used once the US entered World War II in 1941 is unclear; however, they speak to the US Government’s long-running suspicions of the Japanese Empire at the time.