What purpose did the U.S. Congress fulfill by declaring war on Japan after the attack on Pearl Harbor?

The declaration of war on Japan after the attack on Pearl Harbor was primarily about providing for the common defense. This phrase refers to the government's responsibility to protect its citizens and national interests against external threats. The attack on Pearl Harbor on December 7, 1941, constituted a direct and unprovoked assault on American soil by Japanese forces, prompting a national response. By declaring war, Congress took the necessary action to mobilize military resources and engage in a conflict aimed at safeguarding the United States from further attacks and restoring security.

In this context, other purposes mentioned do not directly align with the immediate response required after the attack. Establishing justice and promoting the general welfare are broader concepts and not directly linked to military action against a foreign nation. Ensuring domestic tranquility is more concerned with internal stability rather than addressing foreign aggression. The declaration of war was a decisive step toward reinforcing national security and responding to the threat posed by Japan during World War II.