Prior to the attack on Pearl Harbor, American planners foresaw the possibility of a two-front war. Chief of Naval Operations Harold Rainsford Stark authored the Plan Dog memo, which advocated concentrating on victory in Europe while staying on the defensive in the Pacific. However, the U.S. reassurance to the UK notwithstanding, the U.S.'s immediate concern was with Japan. As Army Chief of Staff General George Marshall later said, "we had a fair understanding of what we had best do rather than the necessity of engaging in prolonged conversations... This understanding, which included a recognition that Germany was the main enemy and that the major effort would be made initially in Europe, was obviously not applicable in the present situation. Of first importance now was the necessity to check the Japanese." Nonetheless, Marshall and other U.S. generals advocated the invasion of northern Europe in 1943, which the British rejected. After Churchill pressed for a landing in French North Africa in 1942, Marshall suggested instead to Roosevelt that the U.S. abandon the Germany-first strategy and take the offensive in the Pacific. Roosevelt "disapproved" the proposal saying it would do nothing to help Russia. With Roosevelt's support, and Marshall unable to persuade the British to change their minds, in July 1942 Operation Torch was scheduled for later that year.