As a Brit, I am a little bemused by the discussion about whether the USA should have interceded, or intervened, in World War II. While not diminishing in any way the value of the US contribution to final victory, or the help given in the form of Lend Lease, surely Americans are taught the historical facts that the USA neither intervened nor interceded. Japan attacked Pearl Harbour, and a few days later the Germans declared war upon the USA. It was not a matter of voluntary intervention. When someone formally declares war, you have little choice other than to engage them.
I hate the idea of causes, and if I had to choose between betraying my country and betraying my friend, I hope I should have the guts to betray my country. E.M. Forster