People underestimate us? All the time? (Mostly Americans )
Guess this would be considered a self observation...

This is ludicrous. Hitler was winning the blockade of Great Briton. He didn't have to win any battles against them, just starve them into peace terms. And without the U.S., he would have.
So Hitler didn't have to win any decisive battles against either side. All he had to do was wait for peace ...