After the Attack on Pearl Harbor and the invasion of Malaya in December 1941, the Empire of Japan was officially at war with the United States and the British Empire. Japan recognised that they would not be able to win a protracted war with the Allied Powers, and suggested that such operations should take no longer than 150 days. They were expecting that Germany would be able to force a British surrender, and subsequently, America would end the war on terms agreeable to Japanese interests.