Key point: In the end, the air attack accomplished what the midget submarines could not.
On Dec. 7, 1941, the aircraft of the Imperial Japanese Navy rained devastation upon the U.S. naval base at Pearl Harbor, Hawaii. But Japanese warplanes didn’t actually fire the first shots that brought America into a massive Pacific War.
An hour before the air attack, a squadron of tiny Japanese midget submarines attempted to slip into the harbor’s defenses, like burglars in the night, to wreak havoc on Battleship Row. Unlike the aerial assault, the sailors failed spectacularly — and the story is often forgotten.
By the 1930s, Imperial Japan and the United States were set on a collision course. Tokyo’s decision to invade China in 1931 and intensify their brutal campaign six years had provoked ultimately irrevocable tensions.
The United States responded to the incursion into China with increasing sanctions, culminating with an embargo on petroleum in July 1941 that crippled the Japan’s economy. Japanese military leaders had wanted to capture the Dutch East Indies to secure its oil wealth, but knew it would trigger war with the Unites States.
While U.S.-Japanese negotiations came within striking distance of a peace agreement, Roosevelt was a hard bargainer, demanding Japan’s leaders order a complete withdrawal from China. They refused.
Thus, Japanese Adm. Yamamoto began planning for a “short victorious war.” The key to this idea was knocking out the battleships of the U.S. Pacific fleet at their home base of Pearl Harbor, Hawaii to buy the Japanese Army time to complete the conquest of the Western Pacific.
Along with a massive air strike from a Japanese carrier task force would constitute the main attack, the Navy coordinated the undersea assault using midget submarines.
During World War II, Japan, England, Italy and Germany all employed midget submarines to stealthily infiltrate shallow, defended harbors and attack vulnerable capital ships. The Japanese Navy’s midget submarines had hidden their developments by calling the ships Type A Kō-hyōteki , or “Target A”
Japanese officials hoped the designation would deceive foreign analysts into believing the 78-feet long submarines were actually mock ships for naval gunnery practice. In reality, each of the 46-ton subs had a crew of two and was armed with two 450-millimeter Type 97 torpedoes with 800 pound warheads.