What was Japan's biggest mistake during world war 2?

Bringing into the war, the most materially productive nation on earth; the United States. During WWII, the United States built enough battleships, cruisers, destroyers, aircraft carriers, fighter planes, bombers, tanks, artillery, cargo ships, submarines, trucks, rifles, machinguns, pistols, bayonets, ammuniton, etc. to supply itself and all of Germany, Japan, Great Britain, France, and the Soviet Union put together!