The vast majority of the USSR factories were funded by american cash. Without the US, Germany wins WW2 handily. Without the USSR, the united states drops nukes on berlin in 1946 and handily wins ww2 by 1947.
Those factories were paid with Soviet money, but many were built by Western companies in the 20s and 30s. Because apparently communism was not such a big deal after all, as long as you could benefit from it.
Germany had already lost the war before Lend-Lease had a significant impact. The offensives of 1941 and 1942 failed before Western aid started arriving in significant quantities. The aid had much more impact on the Soviet offensive, particularly on the logistics side. It can be argued that Lend-Lease won Eastern Europe for the USSR.
As far as I understand, there are two schools of thought on what would have happened without Lend-Lease. In one, the USSR would have won anyway, but the war would have lasted until 1946 or 1947 and it would have been even bloodier and more destructive. In another, the USSR would also have lost, and there would have been an uneasy peace between them and Germany. In both cases, I'd assume the US would not see the Continental Europe worth fighting for.
