The USA did stand up to the Nazis, it just took us a while to get into the fight. :)
The early days of WWII were indeed Britain's finest. Seldom have so many owed so much to so few, and all that.
The many includes the USA, or should. Had Britain rolled over or been conquered in 1940, as the other European countries were, the American attack on Germany would have been infinitely more difficult, arguably impossible, at least before the A-bomb came along.
If you are interested there is an online novella that covers just such an event. Excellent read actually.
Wow, it's on Aamzon now. "The Big One" - Stuart Slade