We all recognize December 7th, 1941 as the day the Japanese swept through Pearl Harbor, leaving behind a wake of destruction that instigated America’s involvement in World War II. How about February 7th, 1932, though? It was well before the Second World War broke out, but tensions were already on the rise between the United States and other countries. It wasn’t an outside attack, however, that makes this a memorable date in US Naval history.

Since 1906, the United States War Department had been on edge over a potential conflict with Japan, so much so that they formulated a strategy known as War Plan Orange. One means of preparing the military for an attack by their Asian opponent was to stage a mock raid, so on February 7th, 1932, that raid took place. Most curious to those who think American officials knew in advance about Japan’s intentions in December of 1941 is that the 1932 raid took place at Pearl Harbor.

The Drill

Rear Admiral Harry E. Yarnell

Dubbed “Fleet Problem #13,” the 1932 drill simulated an attack from a “militaristic, Asian, island nation.” Under the command of Rear Admiral Harry Yarnell, the attacking forces were meant to test the vulnerability of the Pearl Harbor. Utilizing 152 aircraft from a pair of aircraft carriers, the well-trained aviator and admiral was able to achieve a total surprise on Pearl Harbor, starting first by attacking the airfields to disable American ability to counter in the air.

Aside from the location and what was used to attack, the drill shared some striking similarities to the real Pearl Harbor attack. Both Yarnell and the Japanese decided to attack on a Sunday morning when the harbor would off guard. His choice of time was deemed “inappropriate” for an attack despite it actually being the perfect time to catch the harbor with its guard down. The admiral attacked from the north-northeast, similar to how planes would arrive from Japan’s carriers.

Though Yarnell was initially considered the “winner” of the drill, the War Department later changed its ruling. Though the admiral had shown that Pearl Harbor was more than vulnerable to an attack, his warning fell on deaf ears.

Did the US Know?

It does sound like a major coincidence that almost a decade prior to the Japanese attack on Pearl Harbor, the US military was testing that exact scenario. It is, however, not unfathomable to think that if Japan wanted to hit the United States, it would focus on a vulnerable military outpost that would be easy to surprise. With nothing but the deep blue separating Japan and Hawaii, the island chain would make a logical attack point.

The likely truth of the matter is that the United States was simply the victim of a well-planned strike, one that had been previously predicted—almost flawlessly—by the American admiral behind the 1932 attack drill.

Getting to Know the Real Pearl Harbor

You can learn all about the events of December 7th, 1941 at the World War II Valor in the Pacific National Monument. Complete with memorials to the USS Arizona and USS Oklahoma battleships, Pearl Harbor is a fascinating trip through time, starting with the tranquility of that Sunday morning and the first bomb that startled the island into action.