>>510061152oh please, US was fighting Japan for like 4 years and needed the Soviet army to defeat Hitler AND THEN to help them with Japan
only after Hitler was dealt with and Soviet army was rapidly disassembling Japanese defenses did Japan surrender
as for the European theater, you need to know 2 things to realize who made the largest contribution to Nazi's defeat:
1. Nazi's capital
2. Who took it
USSR defeated more than 4/5 of Nazi forces
as for Lend Lease, it started in mid 1941, while the Nazi spine was broken around mid 1943 by USSR, and it started moving to Berlin
so you need to look at the supplies given in these 2 years, and they are far less than the next years
in other words, USSR broke the Nazi spine practically without any help, there was no even a second front
also IIRC British Empire received 3 times more supplies than USSR, and for which US demanded gold after Roosevelt got JFK'ed