I have recently been privy to a debate amongst my friends over the importance of US and UK lend lease on the Eastern Front of WWII. The common thought is that if the US does not enter the war nor conduct lend lease, the Soviets would be delayed but would still be able to crush Germany in the end. However, some argue that western lend lease was needed to feed the Red Army and facilitate their logistics - after all, 2/3 of their trucks were American made. My question is this: if for some reason the US never aided the Soviets and stayed out of the war, would the Soviets have been able to beat back the Germans? For the purpose of the debate, we are assuming that the British are only fighting in North Africa.