[lII1lIlI11ll]

> This labor was, pre-war, a bunch of poor, uneducated serfs (basically slaves).

This is incorrect. Serfdom in Russian empire was abolished in 1861, long before the revolution. Peasant literacy rates, while still poor, had been gradually improving after that.

> Also the USSR had invested leading up to WW2 in agriculture outside Ukraine (since the Nazis controlled it).

What? Not only Ukraine was controlled by Bolsheviks at the start of WW2 its territories have also been extended with parts of Poland and Romania annexed by Soviets between the start of WW2 and the so-called "Great Patriotic" phase of the war.