Was the Japanese attack on Pearl Harbor a surprise attack?

Answer 1

The attack was not a surprise to the US. The Battle of Midway took place only six months after the devastating attack on Pearl Harbor. We had already suffered a series of humiliating and tactically important defeats, but the Americans had at least partially broken the Japanese Naval Code and knew another attack was coming somewhere. We didn't know precisely where, though, until we noticed a code word, "AF," in the Japanese transmissions. We deduced that "AF" was Midway, but we couldn't be sure until we had the garrison at Midway send a radio message "in the clear" (uncoded) that they were having a problem with their fresh water distillery. No sooner had this radio message gone out than a coded message from the Japanese noted that "AF" was having trouble with its fresh water supply. This confirmed that "AF" was Midway, and we were able to begin planning for the big showdown.

The opposing Japanese admiral, Yamamoto, wanted the Americans to come out and fight so that he could sink our remaining carriers. He decided to attack Midway (technically the westernmost island in the Hawaiian chain), a strategically important island because of its literal location midway across the Pacific. It was an important refueling stop for both ships and planes transiting the Pacific. To take it would give the Japanese a base farther to the east than any other, giving them a cushion against attack by the Americans, and Yamamoto also planned to trap the Americans into a battle which would cost them their remaining carriers. Yamamoto was looking for the "decisive battle" that was part of overall Japanese naval strategy. What he got was the "decisive battle," all right, except the Japanese were the losers, not us.

Yamamoto divided his forces in the hope of luring the Americans into thinking that the attacking force was much smaller than it really was, but because we were reading the Japanese codes we practically knew Yamamoto's whole plan, a fact of which Yamamoto was completely ignorant. The upshot was that the surprise was on the Japanese, who lost four of their fleet carriers along with hundreds of irreplaceable veteran pilots. No one knew it at the time, but the Battle of Midway is now recognized as the "turning point" in the Pacific War. After Midway, the Americans were never again on the defensive. The losses to the Japanese Navy could never be made up, and it was from Midway on only a question of time before the Japanese Empire would be defeated.

Answer 2

Yes. The attack on pearl harbor was a military surprise attack, to distract the US and give the Japanese some time to fight Malaysia.

My opinion is this: We Leaked info to the Japanese of the fleet in pearl harbor so that the American people would stand by the decision to try the newly invented hydrogen bomb period!