Would the allies have lost World War II without the U.S.?
The reality is that Germany was losing the war since Stalingrad was over in March 1943. The Battle of Kursk June 1943 made this certain – Hitler threw everything he had left on the Eastern Front (where 80% of his army already was) into a vain attempt at encirclement at the Kursk Salient. The Lucy spy-network tipped off Stalin about Hitler’s plans including the timing of the attack. As a result, the Soviets were able to pre-empt it with a massive artillery-barrage against the Nazis. So I think the final outcome would have been the same, except that Western Europe would have shared the fate of Eastern Europe in terms of being Communist satellites instead of Nazi ones, if the Americans had not intervened. Certainly the British could not have won the war without the US and Soviets. But you have to also remember that it was the Americans and British that destroyed Germany’s fuel-capacity by bombing the refineries. Without that the war would have dragged on years longer, but I still believe