Although stunningly effective in the short term, the attack on Pearl Harbor was a futile military operation. The Japanese started a war they knew they would lose, and did so in a way guaranteed to enrage the enemy. Why the attack was ever made still needs a full explanation. Lack of oil is the textbook answer but the Japanese could have gotten oil from Southeast Asia in ways that were unlikely to start a war with the United States. Pearl Harbor: The Missing Motive examines Japan's history and relations with its neighbors, the lead up to the war, the alternatives available to Japan in 1941, and the surprising yet sound reasoning that led to the Pearl operation.