PEARL HARBOR, Hawaii — Eighty years ago, on Dec. 7, 1941, Japan stunned the United States with an attack on Pearl Harbor.
It was one of the defining moments in American history.
A single carefully-planned and well-executed stroke removed the United States Navy's battleship force as a possible threat to the Japanese Empire's southward expansion. America, unprepared and now considerably weakened, was abruptly brought into the second World War as a full combatant.
Eighteen months earlier, President Franklin D. Roosevelt had transferred the United States Fleet to Pearl Harbor as a presumed deterrent to Japanese aggression. The Japanese military, deeply engaged in the seemingly endless war it had started against China in mid-1937, badly needed oil and other raw materials.
Commercial access to these was gradually curtailed as the conquests continued. In July 1941, the Western powers effectively halted trade with Japan. From then on, as the desperate Japanese schemed to seize the oil and mineral-rich East Indies and Southeast Asia, a Pacific war was virtually inevitable.
By late November 1941, with peace negotiations clearly approaching an end, informed U.S. officials (and they were well-informed, they believed, through an ability to read Japan's diplomatic codes) fully expected a Japanese attack into the Indies, Malaya and probably the Philippines. Completely unanticipated was the prospect that Japan would attack east, as well.
The U.S. Fleet's Pearl Harbor base was reachable by an aircraft carrier force, and the Japanese Navy secretly sent one across the Pacific with greater aerial striking power than had ever been seen on the World's oceans. Its planes hit just before 8 a.m. on Dec. 7.
Within a short time, five of eight battleships at Pearl Harbor were sunk or sinking, with the rest damaged. Several other ships and most Hawaii-based combat planes were also knocked out, and 2,403 Americans were dead. Soon after, Japanese planes eliminated much of the American air force in the Philippines, and a Japanese Army was ashore in Malaya.
These Japanese successes, achieved without prior diplomatic formalities, shocked and enraged the previously divided American people into a level of purposeful unity hardly seen before or since.
For the next five months, until the Battle of the Coral Sea in early May, Japan's far-reaching offensives proceeded untroubled by fruitful opposition. American and Allied morale suffered accordingly.
The Pearl Harbor naval base was recognized by both the Japanese and the United States Navy as a potential target for hostile carrier air power. The U.S. Navy had even explored the issue during some of its interwar "Fleet Problems".
However, its distance from Japan and shallow harbor, the certainty that Japan's navy would have many other pressing needs for its aircraft carriers in the event of war, and a belief that intelligence would provide warning persuaded senior U.S. officers that the prospect of an attack on Pearl Harbor could be safely discounted.
During the interwar period, the Japanese had reached similar conclusions. However, their pressing need for secure flanks during the planned offensive into Southeast Asia and the East Indies spurred the dynamic commander of the Japanese Combined Fleet, Admiral Isoroku Yamamoto to revisit the issue.
His staff found that the assault was feasible, given the greater capabilities of newer aircraft types, modifications to aerial torpedoes, a high level of communications security and a reasonable level of good luck. Japan's feelings of desperation helped Yamamoto persuade the Naval high command and Government to undertake the venture should war become inevitable, as appeared increasingly likely during October and November 1941.
All six of Japan's first-line aircraft carriers, Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku, were assigned to the mission. With over 420 embarked planes, these ships constituted by far the most powerful carrier task force ever assembled. Vice Admiral Chuichi Nagumo, an experienced, cautious officer, would command the operation.
His Pearl Harbor Striking Force also included fast battleships, cruisers and destroyers, with tankers to fuel the ships during their passage across the Pacific. An Advance Expeditionary Force of large submarines, five of them carrying midget submarines, was sent to scout around Hawaii, dispatch the midgets into Pearl Harbor to attack ships there, and torpedo American warships that might escape to sea.
Under the greatest secrecy, Nagumo took his ships to sea on Nov. 26, 1941, with orders to abort the mission if he was discovered, or should diplomacy work an unanticipated miracle. Before dawn on the 7th of December, undiscovered and with diplomatic prospects firmly at an end, the Pearl Harbor Striking Force was less than three hundred miles north of Pearl Harbor.
The Japanese Navy included five Type A midget submarines in the Pearl Harbor raid of Dec. 7, 1941. Transported on board large I-type submarines, the midgets were launched near the entrance to Pearl Harbor the night before the attack was to begin.
One, spotted trying to enter the harbor before dawn, was attacked and sunk by USS Ward (DD-139) in the first combat action of the as yet unopened Pacific War. At least one of the midgets was able to enter the harbor and was sunk there by USS Monaghan (DD-354). Another, the Ha-19, unsuccessful in its attempts to penetrate Pearl Harbor, drifted around to the east coast of Oahu and was captured there the day after the attack.
Four of the five Pearl Harbor midget submarines have been found. That sunk by Ward was located by the Hawai'i Undersea Research Laboratory in late August 2002 in deep water, some five miles off the entrance to Pearl Harbor. It remains where it sank as an element of the Pearl Harbor National Historic Landmark.
The other three have been salvaged. Ha-19 was recovered immediately after the attack and the one sunk by USS Monaghan a few days later. The third was found off the harbor entrance in 1960. The submarine sunk by USS Monaghan's submarine was buried in a landfill shortly after its recovery. Two are on exhibit, Ha-19 at Fredericksburg, Texas, and the one found in 1960 at Eta Jima, Japan.
One of the five Pearl Harbor midgets is still unaccounted for. Recent studies of Pearl Harbor attack photography have led some observers to argue that one of the midgets was in place off "Battleship Row" as the Japanese torpedo planes came in, and may have fired its torpedoes at USS Oklahoma (BB-37) or USS West Virginia (BB-48). This contention is still controversial, but, if it is true, the "missing" Type A midget submarine may lie undiscovered inside Pearl Harbor.
For the Americans, the memory of the "sneak attack" on Pearl Harbor fueled a determination to fight on during WWII. Once the Battle of Midway in early June 1942 had eliminated much of Japan's striking power, that same memory stoked a relentless fight to reverse her conquests and remove her, and her German and Italian allies, as future threats to world peace.
EDITOR'S NOTE: A version of this story was originally published by our sister-station KSDK in 2016.