Japan’s leadership fully supported the raid on Pearl Harbor
The Japanese attack on Pearl Harbor was a hit-and-run raid. There was no intent to invade; the Japanese goal was to inflict as much damage on the Pacific Fleet as possible and retire to the west intact. The primary targets were land-based aircraft, the aircraft carriers in the harbor, and the battleships anchored along Ford Island. If the latter were not in port, targets of opportunity were to be bombed, torpedoed, and strafed. No nation had launched a similar raid of such size, no other Navy had massed together six aircraft carriers, to operate in close coordination with each other. The overall Japanese commander, Admiral Chuichi Nagumo, had never commanded an aircraft carrier, was not a flyer and had little experience with Naval Aviation. Cautious and slow-moving, Nagumo had been a leading opponent of an attack on Pearl Harbor.
Nonetheless, his seniority assured him the command, and he relied on his aides and the captains of the six carriers to carry out the plan to his satisfaction. The Japanese practiced the attack over and over during the summer of 1941, and its operation went more or less like clockwork. One reason that it went so smoothly for the Japanese is the modest resistance they encountered from the stunned Americans at Pearl Harbor. Nearly every possible mistake which the Americans could make that day they made, some repetitively, including miscommunications, lost messages, misidentification of incoming aircraft, ignored warnings, ignored radar captures, and many more. The staff of the Pacific Fleet and the Army charged with defending the Hawaiian Islands were overwhelmed and failed to gain a modicum of control until long after the attacks were over.
The US Army and Navy shared responsibility for the defense of Pearl Harbor in 1941
In January 1941, Secretary of the Navy Frank Knox wrote to Secretary of War Henry L. Stimson, “If war eventuates with Japan, it is believed easily possible that hostilities would be initiated by a surprise attack upon the fleet or the naval base at Pearl Harbor”. Knox went on to identify defenses against air attack, which he deemed “probable”, as inadequate. Knox urged coordination and cooperation between the Navy and Army to defend the installations, though the defense of the island was entirely the responsibility of the Army. Stimson forwarded the letter, with an endorsement supporting its recommendations, to Admiral Husband Kimmel, Commander in Chief Pacific Fleet, and General Walter Short, Commander of the Army’s Hawaiian Department. Through his actions, it was evident Short did not concur with Knox’s assessment of the situation in Hawaii.
Short believed the greatest danger faced by the US Army Air Forces on the Hawaiian Islands came from potential saboteurs, rather than the Japanese Navy. In order to protect his airplanes from sabotage, he ordered them parked in rows on the airfields, wingtip to wingtip, rather than dispersed to protect them from aerial attacks. Short received several war warnings in the week leading up to December 7. In his post-attack defense, he claimed the warnings were vague and did not specifically tell him what to do. He also blamed Navy reconnaissance for not providing him with adequate warnings of Japanese activities. When the Japanese attacked, most of the airplanes the Americans lost that day were destroyed on the ground, the neat rows providing easy targets for the attacking Japanese. The Army relieved Short of his command on December 17, 1941.
The Japanese never considered an invasion of Hawaii in December 1941
During the planning phase for the Pearl Harbor attack, at several junctures the subject of invasion of the Hawaiian Islands arose. As late as September 1941, a proposal was put forth to invade using two divisions of troops, approximately 30,000 men, supported by the carrier strike force and an invasion fleet of about 75-80 ships. Minoru Genda, chief planner for the attack, supported the idea of invasion, believing that occupation of the Hawaiian Islands by the Japanese would force the Americans to sue for peace. Japanese forces in Hawaii threatened the West Coast of the United States, as well as the Panama Canal after America lost most if not all of its Pacific Fleet. Genda went so far as to recommend invasion of Hawaii rather than the Philippines. Preliminary studies indicated it would take the Japanese roughly one month to secure the islands following the initial raids.
In the Japanese military hierarchy, the Imperial Japanese Army (IJA) held sway over their seagoing counterparts. The Army opposed the invasion of Hawaii, largely because it diverted resources from their desired push to the south and east. Japanese war plans of the 1920s and 1930s focused on the seizure of the Philippines, removing the American presence from the Southwest Pacific and providing the Japanese with airbases and naval installations which threatened Australia and New Zealand. The Japanese Navy never formally approached the IJA with plans for an invasion, but private discussions soon indicated the Army would not support the idea. Too many of its resources were already tied up in China or committed to the Philippine Campaign. Whether an invasion of Hawaii would have succeeded remains a source of discussion among theorists and alternative history buffs.
Numerous officials predicted the attack on Pearl Harbor
In October 1941, Lord Louis Mountbatten visited the United States Naval installation at Pearl Harbor. Having recently been assigned to command the British aircraft carrier Illustrious, then under repairs in Norfolk, Virginia, Mountbatten’s ostensible purpose for the visit was to brief American officers over British tactics against the Germans in the Mediterranean. Upon his return, Mountbatten visited Admiral Harry Stark, American Chief of Naval Operations. Mountbatten cited the general lack of preparedness present in Hawaii, in both the fleet and the defensive operations. He made several specific recommendations to Stark, based on the known Japanese penchant for surprise attacks and the British success at Taranto. Few, if any, were implemented. Mountbatten predicted a surprise attack at Pearl Harbor would bring the United States into the war, though he did not say when.
Among his recommendations was the deployment of torpedo nets to protect the battleships in port, which the Navy ignored. Senior Pacific Fleet staff argued the harbor itself offered protection against torpedo attack, being so shallow, and that deployment of the nets hampered other operations. Both the US Army and Navy in Hawaii remained in training status, rather than operational status, a small but significant bureaucratic distinction. Operational units had priority over training units for budget purposes. It also meant that live ammunition for the harbor defenses, and even aboard some ships, remained locked up. Aboard the American battleships, watertight doors remained open, and the ships presented little in the way of material readiness for combat, despite the fleet being under a war warning. Only the carriers were on an operational basis, but they weren’t in Pearl Harbor on December 7.
American security was tight in the days leading to the Pearl Harbor attack
On March 27, 1941, the Japanese liner Nitta Maru arrived in Honolulu carrying a new Japanese Consul-General, Nagao Kita, and his vice-consul, Tadashi Morimura. Both quickly became involved in espionage activities, tasked with obtaining information regarding the American fleet movements to and from Pearl Harbor. Morimura obtained rented quarters near Pearl City, in the hills overlooking the harbor, and studiously avoided the large Japanese-American community in the area. He preferred to take long walks alone in the hills overlooking the harbor, and around other military facilities in the region. He also cultivated a relationship with Bernard Kuehn, an agent working for the German Abwehr. Unknown to the American intelligence community at the time was Morimura was actually a former Japanese naval officer and intelligence agent of the name Takeo Yoshikawa.
Yoshikawa collected intelligence regarding ship movements, troop strengths, anchorages, schedules, and whatever else he could learn from observation and listening. These he transmitted via the Japanese Purple Code at the consulate to his handlers at the Japanese Foreign Ministry. Though the United States had by then broken the Purple Code, and intercepted his reports, no action was taken. The FBI and military intelligence considered most of the messages from the consulate to be commercial in nature, and thus of little interest to the military. Yoshikawa sent information routinely, much of which was used by Japanese commander Yamamoto in finalizing the preparations for the attack. He then destroyed all evidence of his activities. Following the attack, Yoshikawa and other Japanese diplomats were seized by the FBI, but by then no evidence of his espionage activities remained. He was returned to Japan in a diplomatic exchange, never charged as a spy.
Caught by surprise, Americans could do little to fight back
The attack on December 7th came in two waves. The first, detected on radar by the Army station at Opana, was misidentified as an expected flight of B-17s arriving from the mainland. A quick response by the army could have had several American fighters in the air when the Japanese arrived over the military installations, but it was not to be. Several ships outside the harbor also spotted the incoming Japanese; their reports were disregarded while awaiting confirmation. The American air defenses were caught completely by surprise. Nonetheless, during the course of the first wave, which began just before 8.00 AM local time, a handful of American fighters managed to get off the ground and engage the Japanese. After action reports credited six Army Air Force pilots with destroying Japanese aircraft during the attack, most in defense of the several airbases attacked.
Aboard the Navy’s ships, few senior officers were present when the attack began. There were some exceptions, and in some cases, the senior officers arrived aboard in the early stages of the attack. Sailors manned anti-aircraft guns and quickly began shooting at the enemy swarming over them from all directions at once. Aboard USS Nevada, preparations to get underway advanced rapidly. Nevada was the only American battleship to get underway during the attack. As it attempted to leave the harbor it came under such heavy attack, sustaining such severe damage its captain was forced to run the ship aground to prevent it from sinking in the channel, which would have closed the port until the ship could be moved. Oklahoma capsized with such speed hundreds of its crew were trapped below decks. It was during the first wave USS Arizona exploded, raining flaming debris across the oil-strewn harbor.
USS Arizona was responsible for almost half of all American fatalities
The explosion of USS Arizona, which destroyed the entire forward section of the ship, remains a subject of debate eighty years later. One theory is that the fatal bomb, which struck the ship at 8.06, detonated in an area where black powder, used to fire ceremonial salutes, was improperly stored. Another theory suggests the bomb penetrated the armored deck, detonating in the forward magazine. The massive explosion followed the bomb strike by just under 7 seconds, so either theory is possible, but it’s really quibbling over details. The forward magazines exploded, regardless of what the final trigger was, and the result was 1,177 men killed, most of them instantly. More than two-thirds of Arizona’s crew died in the explosion and its immediate aftermath, among them Captain Franklin Van Valkenburgh and Rear Admiral Isaac Kidd. About half of the deaths during the Pearl Harbor attack occurred aboard Arizona.
Arizona’s destruction triggered fires which spread to the oil covering much of the area around Battleship Row and contributed to the loss of at least one more American battleship. USS California, moored alone at the far end of the row, received two bomb hits, and at least two torpedo hits of its own. Its crew lost electrical power temporarily but were in the process of restoring it when burning oil drifted down on the stricken ship. California abandoned ship, but by late morning its crew came back aboard. Attempts to counterflood to control the list on the ship, as well as pumping out the ship, remained hampered by the lack of electrical power. California gradually settled to the harbor mud, its main deck partially awash. Like the other battleships lost that day, other than Oklahoma and Arizona, California was eventually raised, rebuilt, and returned to service.
Pearl Harbor was the major Japanese attack in the Pacific that December
Within a span of less than eight hours following the Japanese strike at Pearl Harbor, American, British, and Dutch possessions in the Pacific also came under attack. In all cases, they struck enemy airfields and, where relevant, Naval installations. American bases in the Philippines, Guam, and Wake Island were assaulted almost simultaneously. All received severe damage and casualties. British installations in Malaya and Singapore, the latter called by Churchill the bastion of the Empire, came under attack. Even before the American Congress heard FDR’s request for a declaration of war against Japan, the British Empire had declared war. Churchill himself directed a British task group, consisting of HMS Prince of Wales and HMS Repulse, to support the defense of Malaya. Both were sunk by Japanese air attack on December 10.
By that time there were already calls across the United States for an investigation into what happened at Pearl Harbor, as well as open accusations of Roosevelt having foreknowledge of the attack. One area of focus among those who believe FDR knew of the impending attack was the absence of the American aircraft carriers from Pearl Harbor. The theory suggests FDR had the Navy remove the carriers to protect them from harm, and ignores naval doctrine of the day. In December 1941, aircraft carriers were not considered capital ships by navies which adopted the Mahan Doctrine (including Great Britain, the United States, and Japan). Battleships and heavy cruisers comprised capital ships, carriers were considered part of the fleet’s scouting forces. The Pearl Harbor debacle led the world’s fleets to reconsider the value of aircraft carriers.
American carriers were absent to prevent them from being attacked
American carriers were absent to prevent they are being attacked, The United States had three aircraft carriers in the Pacific in December 1941. USS Saratoga was in a scheduled refit in Puget Sound. Lexington and Enterprise were both returning from missions during which they reinforced Marine aviation groups, the former at Midway, the latter at Wake Island. Had Enterprise been on schedule, the carrier would have entered port on December 6, after dispatching its air groups to the Naval Air Stations at Pearl Harbor. Heavy weather encountered during its return from Wake Island delayed its arrival by about 24 hours. During the attack, Enterprise was about 200 miles from Pearl Harbor, and planes from its air groups arrived over Hawaii as the attack was underway. Additional aircraft arrived following the Japanese raid and were subjected to friendly fire by the understandably jittery gun crews on the island.
The fact is, the battleships of the US Pacific Fleet were considered by the Navy at the time as the most valuable asset present at Pearl Harbor. Although the United States had other battleships which could be transferred to the Pacific, including Colorado, Idaho, New Mexico, New York, and Mississippi among others, it could ill afford the loss of the ships destroyed on December 7. It was from the Japanese the United States, and Great Britain, learned the value of aircraft carriers massed together as an offensive weapon at sea. With a couple of notable exceptions, the battleship was relegated to task force defense and shore bombardment following the attack on Pearl Harbor. The majority of the surface engagements which occurred in the Pacific during the war involved cruisers and destroyers. Fleet actions involved aircraft carriers, usually well out of sight of each other.
Pearl Harbor remains controversial eight decades on
Following the war, the attack on Pearl Harbor, an assault by a belligerent against a neutral nation, was designated a war crime. A total of 2,403 Americans were killed in the surprise attack, the first of over 100,000 who lost their lives during the Pacific War. During the Tokyo War Crimes Trials, Japanese Prime Minister Hideki Tojo, Navy Minister Shigetaro Shimada, Foreign Minister Shigenori Togo, and Osami Nagano, Chief of the Naval Staff, were charged with and convicted of war crimes involving the Pearl Harbor attack. Yamamoto, who planned the attack, and Nagumo, who commanded the task force which accomplished it, were both dead by then. Conspiracy theorists and revisionists believe FDR should have been charged as well, though the evidence he was aware of the pending attack and deliberately covered it up does not, for the most part, stand up to close examination.
By the late 1990s, the stirring World War II call to “Remember Pearl Harbor” had faded from memory. The attack is barely mentioned in American schools and history textbooks in the 21st century. The grandchildren of Americans who huddled by their radios on December 7, 1941, are largely unaware of the date’s significance. In Japan, schools teach it as just one event in the long war to protect Asia from European colonialization and exploitation, which began in 1931 and continued until the atomic bombing of Japan in 1945. USS Arizona remains where it sank, stripped of all salvageable parts, part of the Pearl Harbor National Memorial. Eighty years after its destruction the hull still seeps fuel oil, a few drops at a time which rise to the surface above, easily seen by those who visit the remains of the ship.
Where do we find this stuff? Here are our sources: