The Japanese dreamed of an Empire in Asia and began their quest in early 1931. They overran Manchuria and established it as a state, which they named Manchukuo. Moving into China, the Japanese were initially successful, but ultimately encountered the resistance of the Chinese, under the government Chiang Kai-shek. A crisis arose in 1937, when Japan launched a major offensive in an effort to reduce China into submission.
When this tactic was unsuccessful, Japan adopted a policy of economic strangulation. By 1939, major coastal ports were seized and the Chinese capital was forced to move from Nanking to the inland area of Hankow.
In 1940, the French allowed the entry of Japanese troops into Indochina. A treaty was made with Thailand (Siam). By the end of 1940 the Japanese were threatening the Burma Road, Chinas last supply line from the outside world. By July 194l, they had completed their occupation of French Indochina and turned their sights to Thailand, Burma and the Philippines.
Concerned over Japans ambitions, the US, Netherlands and Great Britain froze Japanese assets in their countries and imposed stringent economic restrictions, cutting off 90% of raw materials required by Japan for war production. The US demanded the aggressive actions against China and Indonesia be halted. Japan was forced to choose between abandoning her efforts or seizure of other areas rich in raw materials. Abandonment was unthinkable and Japan chose the latter.
By December, 194l the Japanese Army had a force of 2, 400, 000 trained ground troops and an air fleet of 7, 500 planes. The US had a force of 1, 500, 000 of which 1, 000, 000 were not completely trained, 1, 157 combat aircraft and 347 war ships. However, America had already committed to a large portion of war production in the European Conflict.
Japan moved forward with war plans. They believed the US Pacific Fleet at Pearl Harbor was their only threat and set out to neutralize the fleet by means of a surprise air attack.
COMMANDERS OF THE US PACIFIC FLEET
The US, and specifically the Army defenses at Pearl Harbor, was under the Command of Lt. General Walter Short. Shorts military career began during World War I and lasted almost 40 years. After the attack on December 7, 1941, Short requested retirement and was relieved of his duty by Lieutenant General Delos Emmons.
Admiral Husband Kimmel, who served as Commander in Chief of the Pacific Fleet after a long run in the military beginning in 1915, also quickly ended his career after the Pearl Harbor attacks. He served during World War I. He stepped down on December 17, 1941 and was replaced as commander of the Pacific Fleet by Admiral Chester W. Nimitz.
Admiral Kimmel and Lt. General Short shared the same belief: neither expected an attack on Pearl Harbor by the Japanese. Short was consumed by his mission to train his command. Both Short and Kimmel failed to heed any warnings and seldom got together to coordinate efforts between the Army and the Navy.
Throughout the four years that followed the Pearl Harbor Attacks, both Short and Kimmel underwent scrutiny for the choices they made while in command. For years each tried to clear their names. It was not until 2000 that Congress issued a resolution saying that the Japanese attack on Pearl Harbor was not a result of their dereliction of duty and found that both had acted in a competently and professional manner.
WHY WAS THE US UNPREPARED?
The first warning Hawaii received that Japan might attack the US was sent by the Navy to its fleet commanders on October 16, 1941. The Army staff in Washington disagreed with the Navy's warning and the War Department sent a supplementary message to commanders advising they did not see an abrupt change in Japanese foreign policy in the near future. The War Department did not believe that Japan was on the verge of attacking the United States. Under the circumstances commanders of the Pacific Fleet saw no need to do anymore than what was already being done.
There was also an assumption in Washington that Japan had no seaborne aircraft capable of catching the Armys B-24 bombers. They further believed that Japan had overextended their military in other regions and could not concentrate their military forces for a large scale strategic offensive in the Pacific. On the eve of the attack, the Honolulu press reflected the belief of Washington that Japan was too weak to pose a really serious threat to the United States.
There was a complete lack of cooperation between the Army and Navy and no one in authority believed in the dangers to which Pearl Harbor was exposed. Training activities preoccupied the Commanders to the exclusion of adequate preparedness against attack and as they prepared for war, they saw no need for Hawaii to be ready for a large-scale attack.
On December 7, 1941, Washington intercepted a written message from Japan threatening war. The United States did not appreciate the full implications of the 7:30 am Hawaii deadline. A last minute warning was sent to the Pacific commanders, however General Short did not receive the message until hours after the attack. Poor communications between Washington and Hawaii helped the Japanese achieve the surprise attack on Pearl Harbor.
Two early warnings of the approaching Japanese attack came, but however both were ignored. At approximately 6:30 a.m., a Japanese midget sub was spotted and sunk near the entrance to Pearl Harbor. Shortly thereafter, an Army radar station on Oahu's north shore reported the sighting of planes about 50 miles away to the Watch Commander at Army information center at Fort Shafter. It was then reported to a Navy lieutenant. The Navy lieutenant believed they were US planes returning from a reconnaissance flight or B-17s scheduled to arrive from California and the sighting was ignored.