Without our military presence you and the rest of your European cohorts would be speaking german.
It was an Allied effort that defeated Nazi Germany.
- Britain keeping the fight going for 12 months, during which it stood all alone (up until when Hitler made the mistake of attacking the Soviet Union).
- The various resistance groups in occupied Europe (such as the Norwegian one, which destroyed the German's heavy water plant, and thus stopped Hitler from developing a nuclear weapon).
- The much-maligned Soviet Union. Germany's back was broken on the Eastern Front, while the Western Allies mounted a largely ineffective strategic bombing campaign on the German war effort. (Despite an intensifying aerial bombardment on German industry between 1942 and 1944, its war production - tanks, submarines, aircraft, small arms, ammunition etc - just kept on increasing. Thanks largely to the genius of the Nazi's Minister of War Production, Albert Speer, German industry effectively thumbed its nose at the Allied strategic bombing campaign). By the time the Western Allies opened the "Second Front" in June of 1944, the Wermacht was already well and truly on the run in the East.
- And, of course, the USA. Fair to say that once the American industrial system got fully geared for war production, that put the seal on things.
However, it must be stressed that it took an allied effort to defeat Hitler. The USA did not win the war all on its own, as you were trying to suggest.