Short answers, pulled from the story.
The Europe First strategy was a grand policy adopted by the United States and the United Kingdom to prioritize defeating Nazi Germany over Japan. This decision was formalized at the Arcadia Conference in December 1941 following earlier discussions at the ABC-1 conference on the 29th of March 1941.
U.S. leadership refused to alter the strategic direction after the attack on Pearl Harbor on the 7th of December 1941. The balance of forces shifted heavily toward Europe beginning in early 1944 when preparations for the invasion of France intensified.
President Franklin Roosevelt and Prime Minister Winston Churchill convened at the Arcadia Conference to affirm the policy known as Europe First. Fleet Admiral Ernest King strongly believed in Europe First but clashed with General Douglas MacArthur regarding strategic allocation decisions.
Against Japan, the United States deployed 1,873,023 men, 7,857 aircraft, and 713 warships while totals reached 1,810,367 men, 8,807 airplanes, and 515 warships against Germany. By war's end, seventy-eight percent of Army and Army Air Force manpower was deployed against Germany while only 22% went to the Pacific.
A Gallup poll conducted in February 1943 revealed that 53% of Americans identified Japan as their chief enemy while only 34% chose Germany despite its status as the primary threat according to military planners. This public preference for early action against Japan influenced how resources were initially allocated before shifting toward Europe in 1944.