Japanese-American relations cratered in 1941. Japan waged a war of aggression throughout Asia, which strained relations with the United States. The militarists believed war inevitable between the two powers and launched a surprise attack on American forces in Hawaii. Japanese planners hoped the strike would knock America out of the Pacific War. Although Japan caused great damage, the attack on Pearl Harbor only delayed American naval power from retaliating at full strength by six months.
Japan invaded Manchuria in 1931, which eventually led to an outbreak of a full scale war with China in 1937. The Japanese also attacked the American vessel USS Panay, massacred thousands in Nanking, and invaded Vietnam. The American government protested these moves and initiated embargoes against the aggressors. Negotiations between the two nations faltered and Japan decided to strike.
The militarists hoped to destroy the American fleet at Pearl Harbor while their emissaries discussed peace in Washington D.C. The destruction would keep the Americans out of the Pacific and Southeast Asia and allow Japan to consolidate conquests. They believed America would not be able to launch an offensive and challenge the Imperial Navy on the seas for some time. Japan felt completely confident in their ability to devastate the American force at Pearl Harbor.
Admiral Yamamoto planned to strike Pearl Harbor after Japanese diplomats delivered formal notification that peace talks had ended. However, this did not occur and the attack occurred before anyone in Washington was wise. The first wave of 183 Japanese planes was detected by radar, but the officer on duty believed it was a group of American bombers returning to base.
The actual attack began at 7:48 A.M. Hawaiian time on December 7, 1941. The Japanese quickly bombed battleship row to eliminate the capital ships. Dive bombers struck the airfields across Oahu. Meanwhile, a second wave of 171 fighters struck Ford Island and a field near Kaneohe. It appeared the Japanese had delivered their crippling blow.
The attackers caught the Americans completely unprepared. Ammunition was locked, planes were lined up wingtip to wingtip to protect against sabotage, and battle stations unmanned. Japan sunk four battleships, two other vessels, and destroyed nearly 200 aircraft. They damaged three battleships, nine other major vessels, and around 150 planes. 2,400 men died and over 1,200 were wounded in the attack. Japan prepared a third wave strike, but the American aircraft carriers were not at Pearl Harbor. As a result, Admiral Nagumo decided to withdraw. He worried that American carriers and their planes would appear and wipe out the Japanese fleet while their own planes were conducting operations at Pearl Harbor. Additionally, fuel reserves ran low and the weather was changing for the worse.
In addition to the success at Pearl Harbor, Japan also attacked the Philippines, Aleutian Islands, and several British colonies. They drove General MacArthur and the Americans out of the Philippines. MacArthur swore to return. Meanwhile, Japanese forces remained stranded in the Aleutians for years.
A shocked President Franklin Roosevelt addressed the nation and called the attack “cowardly.” The infamy speech laid out the rationale for war against Japan and described the attack for listeners. The war went poorly for the Americans at first. However, American industrial might finally came to full power and the U.S. replaced the losses in men and materiel. In June, 1942, the U.S. navy halted the Japanese Pacific advance and General MacArthur began rolling back Japanese gains. The attack bought Japan six months.
The surprise attack on Pearl Harbor shocked and saddened the United States. Over 2,400 men died in the Japanese assault. However, the attack did not damage the American war machine as Japanese planners hoped. Instead, it angered the nation and allowed Japan to run unimpeded for only six months. Eventually, the U.S. recovered and slowly rolled back Japanese forces.