The "Europe first" policy of the United States had initially only allowed for defensive actions against Japanese expansion, in order to focus resources on defeating Germany. However, Admiral King's argument for the Guadalcanal invasion, as well as its successful implementation, convinced Roosevelt that the Pacific Theater could be pursued offensively as well. By the end of 1942, it was clear that Japan had lost the Guadalcanal campaign, a serious blow to Japan's strategic plans for the defense of their empire and an unanticipated defeat at the hands of the Americans.