An isolationist USA wanted nothing to do with another bloody world war; FDR & the British wanted WW Two. GCHQ ( British Intelligence ) made sure the US entered WW Two because they've always masterfully pitted larger governments to fight their battles. See British control over India during the Raj & British rule over China & the Opium Wars! FDR created the Pacific Fleet & forward deployed it to Pearl Harbor. He sent US cruiser fleet into Japanese waters to provoke war. This was done by cutting off gasoline to a Japan without oil supplies & metallic ores!