December 7 is the day that lives on in infamy, when a Japanese naval force traveled across the Pacific unobserved by ships or planes, under the nose of our intelligence network, to catch the US fleet napping early one Sunday morning. Fortunately the newer more valuable American ships, including all our aircraft carriers, had quietly been sent on maneuvers.
The sneaky nature of Japan’s attack, combined with her similar blitz on our colonial possessions in the Pacific, made War With Japan an easier sell to isolationist Americans who were redoubled in their resolve after the disaster of our unnecessary participation in WWI. It’s conjectured that FDR knew about the Attack on Pearl Harbor, but understood that only such infamy would prompt our public to cry for revenge.
Whether or whatever Roosevelt knew, he is blamed certainly for having given the Japanese no alternative but to attack. The US was asserting itself as lone strong man in the Pacific, with expansionist designs of its own, and had issued an ultimatum to Japan that we would brook no territorial ambitions of theirs. We’d already cut off Japan’s access to oil, American volunteers were already fighting Japan in China, and our bases stood in their way in the Philippines. America had assumed Spain’s stewardship responsibilities over the Philippines just as the Filipinos were about to seize their independence.
So Japan was goaded into trying to hobble our Pacific fleet, hoping to smack down our bullying tone. But they clobbered only our older ships and unwittingly unleashed an industrial giant, which our leaders knew, and they would learn, would prove unstoppable.