Let me correct their weapons weren't good enough against MIGHTY SOVIET UNION. Other allies were just some little fly farts. Russians were the ones that won the war they are the ones you should thank for winning, too much Hollywood now days.
I would be interested to see what the result would have been without the support from the US. Steel, other raw materials, fuel, lubricants, machines, complete factories, clothes, shoes, food... not to mention 2,000 locomotives, 11,000 rail cars, 18,700 aircraft, enough trucks that by the fall of Berlin 2/3 of Red Army trucks were still US-made, etc. 4,000 M4 Shermans, 1,300 M3 Lees, 1,700 M3 Stuarts might seem small numbers but were delivered at the most critical stage when T-34 production was still gearing up.