Its important to point out that American entry into WW2 did not establish American hegemony, but only accelerated it. Roosevelt had been supplying Allied forces

Its important to point out that American entry into WW2 did not establish American hegemony, but only accelerated it. Roosevelt had been supplying Allied forces with Material for a long time before Japan bombed Pearl Harbor (from historical records, its pretty clear that the Japanese understood it was only a matter of time before the US entered the war and thus attacked pre-emptively). The event that solidified US as the superpower was actually the Suez crisis, where the UK and French had to begrudgingly agree to American demands, making it clear who was the top dog.