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Pearl Harbor Day 2009: three enduring mysteries

On Pearl Harbor Day 2009, here is a look at lingering questions such as: How did the Japanese fleet get so close to Hawaii without being spotted?

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But the radar return looked much different from what they were used to seeing.

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"Why didn't this stir up their curiosity?" Suid says.

Why did the US Navy ignore the sinking of a Japanese submarine prior to the attack? At 6:37 on the morning of Dec. 7, the USS Ward, an old four-stack destroyer, attacked and destroyed a Japanese mini-sub making its way toward Pearl Harbor.

Crew members of the Ward saw a submarine periscope, dropped depth charges, and saw an oil slick and debris indicating they had destroyed a target. They immediately sent a dispatch saying that they had destroyed "a submarine operating in defense sea areas," according to a copy of the ship's report of the attack.

This incident took place an hour prior to the arrival of the first wave of Japanese warplanes. But US military officials did not heed the warning provided by the Ward, or did not believe it, or simply were unable to react in time.

Three years later to the day, on Dec. 7, 1944, the Ward was sunk by a Japanese kamikaze air attack off the island of Leyte.

How did the Japanese fleet get so close to Hawaii without being spotted? The Japanese military's attempts to deceive its US counterparts as to where Japan's carriers were in early December 1941 succeeded to a remarkable degree.

A radio ruse contributed greatly to this success. Beginning in mid-November, the Japanese ships pretended to be continuing with a routine communications drill – knowing that all the while US eavesdroppers were listening in.

They then followed with a week of only occasional chatter, leading US analysts to believe that the carriers had entered home waters for rest. Instead, they were steaming toward Hawaii.

Japanese operational security prior to the fleet's departure had been so tight that at least one foreign ship approaching a Japanese navy training area had been boarded and seized. Fleet plans for the month of December had been printed without an annex detailing the destination of Hawaii. Even senior Japanese officers weren't told of the attack until the last possible moment.

In the end, the Japanese achieved almost complete tactical surprise. And in that might lie the key to understanding Pearl Harbor, writes Hanyok, the former NSA historian.

The key could be not the surprise per se, but the skill of the Japanese. Most US analyses of Pearl Harbor probe for American mistakes, or they at least see the attack in an American frame of reference.

"But the key to understanding why the surprise assault was so successful lies in realizing what the Japanese did right," according to Hanyok.

[Editor’s note: The original version cited the wrong year twice.]


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