Before the attack on Pearl Harbor, the 800,000-member America First Committee vehemently opposed any American intervention in the European conflict, even as America sold military aid to Britain and the Soviet Union through the Lend-Lease program. Opposition to war in the U.S. vanished after the attack. On 8 December, the United States, the United Kingdom, Canada, and the Netherlands declared war on Japan, followed by China and Australia the next day. <answer>Four</answer> days after Pearl Harbor, Nazi Germany and Fascist Italy declared war on the United States, drawing the country into a two-theater war. This is widely agreed to be a grand strategic blunder, as it abrogated the benefit Germany gained by Japan's distraction of the U.S. (predicted months before in a memo by Commander Arthur McCollum)[nb 12] and the reduction in aid to Britain, which both Congress and Hitler had managed to avoid during over a year of mutual provocation, which would otherwise have resulted.
How many days after the attack on Pearl Harbor did Germany wait to declare war on the United States?
Four