Pearl Harbor

Pearl Harbor

The road to war between Japan and the United States began in the 1930s when differences over China drove the two nations apart. In 1931 Japan conquered Manchuria, which until then had been part of China. In 1937 Japan began a long and ultimately unsuccessful campaign to conquer the rest of China. In 1940, the Japanese government allied their country with Nazi Germany in the Axis Alliance, and, in the following year, occupied all of Indochina.

The United States, which had important political and economic interests in East Asia, was alarmed by these Japanese moves. The U.S. increased military and financial aid to China, embarked on a program of strengthening its military power in the Pacific, and cut off the shipment of oil and other raw materials to Japan.

Because Japan was poor in natural resources, its government viewed these steps, especially the embargo on oil as a threat to the nation's survival. Japan's leaders responded by resolving to seize the resource-rich territories of Southeast Asia, even though that move would certainly result in war with the United States.

The problem with the plan was the danger posed by the U.S. Pacific Fleet based at Pearl Harbor. Admiral Isoroku Yamamoto, commander of the Japanese fleet, devised a plan to immobilize the U.S. fleet at the outset of the war with a surprise attack.

The key elements in Yamamoto's plans were meticulous preparation, the achievement of surprise, and the use of aircraft carriers and naval aviation on an unprecedented scale. In the spring of 1941, Japanese carrier pilots began training in the special tactics called for by the Pearl Harbor attack plan.

In October 1941 the naval general staff gave final approval to Yamamoto's plan, which called for the formation of an attack force commanded by Vice Admiral Chuichi Nagumo. It centered around six heavy aircraft carriers accompanied by 24 supporting vessels. A separate group of submarines was to sink any American warships which escaped the Japanese carrier force.

Nagumo's fleet assembled in the remote anchorage of Tankan Bay in the Kurile Islands and departed in strictest secrecy for Hawaii on 26 November 1941. The ships' route crossed the North Pacific and avoided normal shipping lanes. At dawn 7 December 1941, the Japanese task force had approached undetected to a point slightly more than 200 miles north of Oahu. At this time the U.S. carriers were not at Pearl Harbor. On 28 November, Admiral Kimmel sent USS Enterprise under Rear Admiral Willliam Halsey to deliver Marine Corps fighter planes to Wake Island. On 4 December Enterprise delivered the aircraft and on December 7 the task force was on its way back to Pearl Harbor. On 5 December, Admiral Kimmel sent the USS Lexington with a task force under Rear Admiral Newton to deliver 25 scout bombers to Midway Island. The last Pacific carrier, USS Saratoga, had left Pearl Harbor for upkeep and repairs on the West Coast.

At 6:00 a.m. on 7 December, the six Japanese carriers launched a first wave of 181 planes composed of torpedo bombers, dive bombers, horizontal bombers and fighters. Even as they winged south, some elements of U.S. forces on Oahu realized there was something different about this Sunday morning.

In the hours before dawn, U.S. Navy vessels spotted an unidentified submarine periscope near the entrance to Pearl Harbor. It was attacked and reported sunk by the destroyer USS Ward (DD-139) and a patrol plane. At 7:00 a.m., an alert operator of an Army radar station at Opana spotted the approaching first wave of the attack force. The officers to whom those reports were relayed did not consider them significant enough to take action. The report of the submarine sinking was handled routinely, and the radar sighting was passed off as an approaching group of American planes due to arrive that morning.

The Japanese aircrews achieved complete surprise when they hit American ships and military installations on Oahu shortly before 8:00 a.m. They attacked military airfields at the same time they hit the fleet anchored in Pearl Harbor. The Navy air bases at Ford Island and Kaneohe Bay, the Marine airfield at Ewa and the Army Air Corps fields at Bellows, Wheeler