Attack on Pearl Harbor (1941): The Day the US Went to War

The attack on Pearl Harbor was a surprise strike by Japanese carrier aircraft on the US Pacific Fleet at its base in Hawaii on the morning of Sunday, 7 December 1941. In under two hours, the raid sank or damaged all eight battleships in the harbour and killed 2,403 Americans. It brought the United States into the Second World War and turned a European and Asian conflict into a truly global one.

Background

During the 1930s Japan expanded into China, beginning with Manchuria in 1931 and full-scale war from 1937. The United States opposed this expansion and gradually tightened economic pressure. In 1940 the US Pacific Fleet was moved from California to Pearl Harbor on the island of Oahu as a deterrent.

After Japan occupied southern French Indochina in July 1941, the United States froze Japanese assets and, together with Britain and the Netherlands, cut off oil exports. Japan imported most of its oil, much of it from the United States, and its leaders feared their navy and economy would grind to a halt within a year or two.

Negotiations in Washington continued through the autumn, but neither side would give way on China. On 26 November 1941 Secretary of State Cordell Hull presented a note demanding Japanese withdrawal from China and Indochina, terms Japan’s government regarded as unacceptable. By then Tokyo had already decided on war if diplomacy failed.

Planning the attack

The plan was the work of Admiral Isoroku Yamamoto, commander of Japan’s Combined Fleet. He believed Japan could not win a long war against American industry, but that a crippling first blow might buy time to seize South-East Asia and build a defensive perimeter. The detailed air plan was developed by officers including Commander Minoru Genda, and shallow-running torpedoes were adapted for the harbour’s shallow water.

The strike force, commanded by Vice Admiral Chūichi Nagumo, included six aircraft carriers: Akagi, Kaga, Sōryū, Hiryū, Shōkaku and Zuikaku, with battleships, cruisers, destroyers and tankers in support. It left Hitokappu Bay in the Kuril Islands on 26 November and crossed the North Pacific in radio silence. On 2 December the coded signal “Climb Mount Niitaka” confirmed that the attack would go ahead.

Five midget submarines were also sent to penetrate the harbour. At the same time, Japanese forces prepared attacks on Malaya, the Philippines, Hong Kong, Guam and Wake Island.

What happened

Early that morning, the destroyer USS Ward fired on and sank a midget submarine near the harbour entrance, and an army radar station at Opana Point detected a large group of aircraft approaching. Neither warning led to a general alert; the radar contact was assumed to be a flight of American B-17 bombers expected from the mainland.

At 7:48 a.m. local time the first wave of 183 aircraft, led by Commander Mitsuo Fuchida, struck. Fuchida sent the signal “Tora! Tora! Tora!” to report that surprise had been achieved. Torpedo bombers attacked the battleships moored along “Battleship Row” beside Ford Island, while dive bombers and fighters hit the airfields at Hickam, Wheeler, Kaneohe, Ewa and Ford Island, destroying many aircraft parked wingtip to wingtip as a precaution against sabotage.

At about 8:10 a.m. an armour-piercing bomb penetrated the forward magazine of USS Arizona, which exploded and sank with 1,177 of her crew. USS Oklahoma capsized after several torpedo hits, trapping hundreds of men. A second wave of about 170 aircraft arrived around 8:55 a.m. and attacked ships and airfields again. USS Nevada, the only battleship to get under way, was badly hit and deliberately beached to avoid blocking the channel.

Many sailors and soldiers fought back despite the surprise. Anti-aircraft gunners opened fire within minutes, and a handful of US Army pilots managed to take off and shoot down several attackers. Doris Miller, an African American mess attendant aboard USS West Virginia, helped carry wounded men and fired a machine gun at the attacking aircraft; he became the first African American to receive the Navy Cross. Rescue teams later cut through the hull of the capsized Oklahoma and saved 32 trapped men.

By about 10 a.m. the attackers had gone. Nagumo decided against a further strike on the fuel tanks, repair yards and submarine base, a decision that historians have debated ever since.

Losses

One Japanese midget submarine officer, Kazuo Sakamaki, was captured, becoming the first Japanese prisoner of war taken by the United States.

Key people

Isoroku Yamamoto conceived the attack. He had studied in the United States and warned that Japan could not win a long war against it, yet he planned the strike he believed offered Japan’s best chance.

Chūichi Nagumo commanded the carrier striking force and made the cautious decision to withdraw after two waves.

Mitsuo Fuchida led the air attack and later wrote widely read, though not always reliable, accounts of it.

Admiral Husband E. Kimmel and Lieutenant General Walter Short, the navy and army commanders in Hawaii, were relieved of command after the attack and blamed for unpreparedness, a judgement later historians and investigations have softened.

Franklin D. Roosevelt led the nation into war the next day.

Consequences

On 8 December 1941 Roosevelt addressed Congress, calling 7 December “a date which will live in infamy”. Congress declared war on Japan with only one dissenting vote, cast by Representative Jeannette Rankin. On 11 December Germany and Italy declared war on the United States, and the United States responded in kind. American public opinion, previously divided over intervention, united behind the war effort.

In the short term Japan’s gamble succeeded. With the battle fleet out of action, Japanese forces swept across South-East Asia and the Pacific, capturing the Philippines, Malaya, the Dutch East Indies and, in February 1942, the great British base in the Fall of Singapore.

But the attack missed the US carriers, which were at sea or on the mainland, and left the oil storage and repair facilities largely intact. Six of the eight battleships were eventually repaired and returned to service. In June 1942 American carriers defeated the Japanese fleet at the Battle of Midway, sinking four of the six carriers that had attacked Pearl Harbor.

The attack also had grim consequences at home. Fear and prejudice after Pearl Harbor led to Executive Order 9066 in February 1942, under which about 120,000 people of Japanese ancestry, most of them American citizens, were removed from the West Coast and held in camps. The United States formally apologised and paid compensation in 1988.

Investigations, myths and facts

Several official inquiries examined how the fleet could be caught by surprise. They found failures of communication, analysis and readiness. A long Japanese diplomatic message breaking off negotiations was meant to be delivered just before the attack, but delays in decoding and typing it at the Japanese embassy meant it reached Hull after the bombs had fallen.

“Roosevelt knew and let it happen.” This theory has circulated since the 1940s, but historians have found no reliable evidence for it. American codebreakers could read Japanese diplomatic messages, but these did not reveal the target, and the navy’s own codes for the strike force were not being read.

“The attack destroyed the US Navy.” It was a heavy blow to the battleship force, but the carriers, submarines, fuel stocks and shipyards survived, and these mattered most in the war that followed.

Legacy

The USS Arizona Memorial, built over the sunken battleship and dedicated in 1962 after a public fundraising campaign, is now part of Pearl Harbor National Memorial and is visited by well over a million people a year. Small amounts of oil still seep slowly from the wreck to the surface, more than eighty years later. The phrase “Remember Pearl Harbor” became a wartime rallying cry, and the attack remains a defining reference point for surprise attacks and intelligence failures. Yamamoto himself was killed in 1943 when US fighters shot down his aircraft, as described in the article on his death.

Timeline

• 1941, July: Japan occupies southern French Indochina; the US freezes Japanese assets and halts oil exports.
• 1941, 26 November: The Japanese strike force sails from Hitokappu Bay; Hull delivers his note in Washington.
• 1941, 2 December: The signal “Climb Mount Niitaka” confirms the attack.
• 1941, 7 December, about 6:40 a.m.: USS Ward fires on a midget submarine near the harbour entrance.
• 1941, 7 December, 7:48 a.m.: The first wave of Japanese aircraft attacks.
• 1941, 7 December, about 8:55 a.m.: The second wave arrives.
• 1941, 8 December: Roosevelt’s “infamy” speech; the US declares war on Japan.
• 1941, 11 December: Germany and Italy declare war on the United States.

Why it matters

Pearl Harbor brought the world’s greatest industrial power into the Second World War, sealing the long-term fate of Japan and Germany. It also changed American foreign policy for good, ending the country’s interwar isolationism and setting it on the path to global leadership after 1945.