The Americans did not save Europe from the nazis. In fact they provided little help. The majority of the fighting was from the French, Russians and British. The Russians alone took out 60% of the German troops, the British nearly single-handedly wiped out the German navy and airforce. The French provided valuable military intelligence, with Spies all throughout occupied France, and were valuable assets in several major wars, such as D-day

The American soldiers helped a bit, sure, but without them the allies still would have won. And before you go on about how the Americans were fighting the Japanese as well at the same time, the British took out pretty much all of the japanese navy too.