Background

Japan was hit hard by the Great Depression of the early 1930s. Japanese disappointment with the moderate government gave way to a militant government. In 1931 Japan occupied Manchuria in northern China. Over the next decade conflicts broke out and war was declared on China in July 1937. As Japanese hostility increased, its relationship with the United States declined. Occupied Manchuria was exploited by Japan with the creation of heavy and light industries. This was essential for Japan because it did not have the necessary natural resources. Japan’s pursuit for other supplies drove foreign and military policy throughout the decade and eventually led to the attack on Pearl Harbor and war in the Pacific during World War II.

Japan’s need for resources increased as relations with the U.S. declined further. In the past, Japan relied on the U.S. to supply many natural and industrial resources. The United States was increasingly alarmed by Japanese aggression and let a commercial treaty dating back to 1911 lapse in January of 1940. In July the U.S. started restricting the sale of scrap iron and aviation fuel to Japan. In reaction, the Japanese signed the Tripartite Pact with Germany and Italy. This made Japan an official member of the Axis alliance and brought them into World War II. This created major problems for the United States. Officially, the U.S. was neutral, but there was no doubt where American sympathies rested. President Franklin D. Roosevelt had already put his stance of neutrality in jeopardy by supplying Britain with money and arms for the war under the "lend-lease" agreement. The Tripartite Pact meant that any supplies that might be delivered to Japan would be indirectly helping Germany and Italy.

In response President Roosevelt froze all Japanese assets in the U.S. and ended trade with Japan in July 1941. For Japan, involved in a long war with China, this was devastating. With its survival threatened, Japan widened its search for an alternate supply of resources. Japan focused on Southeast Asia because of its rich supply of minerals and oil. German success in Europe in 1940 had left control of previously French and Dutch colonies up for grabs in Southeast Asia.

Japan realized that a full-blown invasion of Southeast Asia would almost certainly trigger war with America. It needed to find a way to ensure that the United States did not interfere with the invasion of key areas like the Philippines, Burma, and Malaya. The Japanese government decided to attack the American naval base Pearl Harbor on the Hawaiian island of Oahu. By destroying the United States’ Pacific Fleet, Japan expected to eliminate the American military presence from the Pacific for enough time to allow it to acquire the resources it needed so urgently. Japan also hoped to crush American morale with their attack. Little did they know that they had awakened a “sleeping giant.”

In 1941 President Roosevelt stationed fifty B17 bombers in the Philippines, standing between the Japanese and Dutch East Indian oil fields they needed so badly. Roosevelt also ordered the U.S. Fleet to the Pacific. On December 2, 1941, Hawaii received a message from Washington that began, “This is a war warning.” After deciphering a Japanese code message, the U.S. knew Admiral Yamamoto was preparing for a Pacific attack, but not when or where. No one believed it would be Pearl Harbor. A week later that belief would have a dreadful cost.

A Japanese Navy "Zero" fighter takes off from the aircraft carrier Akagi, on its way to attack Pearl Harbor on the morning of December 7, 1941.		The forward magazine of USS Shaw explodes during the second Japanese attack wave. Photographed from Ford Island
View looking up "Battleship Row" on 7 December 1941, after the Japanese attack. The sunken and burning USS Arizona is in the photo’s center. To the left of her are USS Tennessee and the sunken USS West Virginia.		Planes and hangars burning at Wheeler Army Air Field, Oahu, soon after it was attacked, as seen from a Japanese Navy plane.