You could say soviets did all the WW2 heavy lifting, starting with

https://en.wikipedia.org/wiki/Kama_tank_school

https://en.wikipedia.org/wiki/Lipetsk_fighter-pilot_school

https://en.wikipedia.org/wiki/Tomka_gas_test_site and

and culminating in https://en.wikipedia.org/wiki/Molotov%E2%80%93Ribbentrop_Pac...