The British were on the war before the Americans and were losing. Without the Americans the Germans would have won.
Sounds like your partner doesn't know a thing about WWII. Or military strategy... Or plain GRATITUDE.
I'm sorry, but that WWII comment irks me. 3 dead American soldiers were left on Normandy, for every soldier that made it. It was what it took to take over a heavily fortified territory from the Germans. Europe had been on the war for years and had no soldiers to lose in that ratio, not even the brits did.
According to Sun Tzu, one of the best strategists in history, to conquer a territory occupied by an enemy you need either a force 4 times as big ( or as mighty) as the enemy or you have to go for guerrilla war. The Americans provided the 3X troops to die to free Europe, the Europeans gave the rest.
It may sound funny to joke about it 50 years later, now that all is well, but it is very ignorant IMHO. Those 3 that died for every live soldier had families and friends and absolutely no obligation to bail Europe out, you know ?

























