"BTW I believe there were a few other countries involved in fighting during WW2, amazing how SOME of you think you won it single handedly, yes you were the biggest, and may be the strongest, BUT YOU WERE NOT ALONE!!! It was a team effort. Seems to be alot of our boys ended up on a beach somewhere never to come home too!"
I believe the key distinction made is that the United States was pretty safe from any expansionist worried from Germany. The United States would have been better off, from a selfish perspective, to focus its attention solely on Japan. Instead, the United States sacrificed tens of thousands of its own to protect its friends in Europe, something no country has ever done for it.