Pearl Harbor II

Pearl Harbor II

The preemptive Japanese Navy attack on Pearl Harbor brought the United States into World War II (1939–1945). Supreme commander of the Japanese fleet Admiral Yamamoto Isoroku developed a plan to gain time for the Japanese to establish a defensive ring in the Southwest Pacific. The previous strategy was to carry out the southern conquests while the battle fleet waited in home waters for the arrival of the U.S. Pacific Fleet, which they hoped would be savaged by Japanese torpedo and air attacks on the long voyage to the Far East.

Yamamoto took advantage of the fact that in the summer of 1940 President Franklin Roosevelt had ordered the Pacific Fleet relocated from San Diego, California, to Pearl Harbor in the Hawaiian Islands. Yamamoto believed that the United States would need two to three years to recover from a blow at Pearl Harbor, giving the Japanese time to build up their defensive ring. He also hoped that the attack might cause the United States to lose heart and negotiate with Japan. As the Japanese gathered intelligence through their Honolulu consulate, their fleet, already possessing the world’s finest naval air arm, went through intensive training.

The Japanese plan took advantage of the recently increased range of the Zero fighter. The British attack on the Italian fleet at Taranto on November 11, 1940, had shown that torpedo attacks by aircraft were possible in shallow waters. Japanese bombers also carried armor-piercing shells fitted with fins. Dropped vertically as bombs, no deck armor could withstand them.

The Japanese knew that Pacific Fleet commander Admiral Husband E. Kimmel brought the fleet back into Pearl Harbor on weekends, and the ships would not be fully manned then. A Sunday was the natural choice for the attack, and after midDecember the weather was likely to be unfavorable for concurrent Japanese amphibious landings in Malaya and the Philippines. On the night of December 6–7 there would be no moonlight, aiding the surprise approach. The chief Japanese targets were the carriers, next the battleships, and then oil tanks, port facilities, and aircraft on the ground.

Vice Admiral Nagumo Chumichi commanded the Japanese task force. It was centered on six carriers with 411 aircraft, of which 360 were slated to be employed in two attack waves (350 actually took part, 183 in the first wave and 167 in the second). These numbered 129 high-level bombers, 103 dive-bombers, 40 torpedobombers, and 78 fighters. Escorting the strike force were two battleships, three cruisers, nine destroyers, three submarines, and eight tankers. The air strike was to coincide with an attack by midget submarines.

The submarines departed Japan on November 21, while the carrier strike force sortied on November 26. The Japanese arrived off the Hawaiian Islands undetected, and Nagumo ordered the aircraft launched some 275 miles north of Pearl Harbor between 6:00 and 7:16 a.m. (Hawaii time) on December 7. The Japanese submarines were detected, and U.S. destroyers sank one at 6:51 a.m. and another at 7:00 a.m. Radar warned of the approaching aircraft, but this was interpreted as B-17s coming from the mainland and was therefore ignored.

Of eight U.S. battleships at Pearl Harbor, the Japanese sank four and severely damaged the others. Damage to the infrastructure of Pearl Harbor was superficial. In two strikes the Japanese sank three destroyers and four smaller vessels and damaged three light cruisers and a seaplane tender. Some 188 American aircraft were destroyed, and 63 were badly damaged; most had been packed together to protect against ground sabotage. The Japanese lost only five midget submarines along with 29 planes destroyed and 70 damaged. U.S. casualties totaled 3,535 people killed or wounded; Japanese killed were fewer than 100.

Ultimately all U.S. battleships were refloated except the Arizona, and all of these except the Oklahoma saw subsequent service. The loss of U.S. life in the attack, while tragic, was not catastrophic for the subsequent U.S. war effort and certainly was far less than what it would have been had the fleet been caught at sea.

Thanks to the attack, the Japanese could carry out their operations in the Southwest Pacific without threat of U.S. naval interference. They also gained time to extend and build up their defensive ring. The main drawbacks were that the strike missed the chief target, the U.S. carriers, which were on ferrying duties. Had the Japanese mounted an additional strike and destroyed the oil tanks and facilities, the Pacific Fleet would have been forced to relocate to San Diego. Nagumo did not want to risk his own ships, however. He had achieved his objectives at virtually no cost and worried about the location of the U.S. carriers. The fleet would return home.

Although their attack had a historical parallel in their strike without declaration of war on the Russian fleet at Port Arthur in 1904, the Japanese had intended to keep within the bounds of legality. They planned to present a declaration of war to the U.S. government a half hour before the attack, but the declaration’s extreme length and delays in decoding it at the Japanese embassy in Washington meant that it was not ready for delivery until a half hour after the attack.

The failure of the carefully scripted Japanese scenario secured the moral high ground for Washington on what President Franklin Roosevelt referred to as “a day that will live in infamy.” This was the primary negative for Japan. Coming without declaration of war, the attack aroused such anger in the United States as to sweep away any isolationist sentiment and mobilize the entire nation behind the war effort.

For Americans the air strike on Pearl Harbor produced widespread criticism of the authorities and suspicion that factors beyond mere ineptitude were responsible for the disaster. These conspiracy theories have persisted, but there is no proof that Roosevelt knew about the Japanese plan or sought Pearl Harbor as a means of bringing the United States into the war.


Morison, Samuel Eliot. History of United States Naval Operations in World War II, Vol. 1, The Rising Sun in the Pacific, 1931–April 1942. Boston: Little, Brown, 1948.

Prange, Gordon W., with Donald M. Goldstein and Katherine V. Dillon. At Dawn We Slept: The Untold Story of Pearl Harbor. New York: McGraw-Hill, 1981. ———.

Pearl Harbor: The Verdict of History. New York: McGraw-Hill, 1986.