 The decision by Japan to attack the United States remains controversial.Study groups in Japan had predicted ultimate disaster in a war between Japan and the U.S., and the Japanese economy was already straining to keep up with the demands of the war with China.However, the U.S. had placed an oil embargo on Japan and Japan felt that the United States' demands of unconditional withdrawal from China and non-aggression pacts with other Pacific powers were unacceptable.