In the first battle of Kiev the USSR lost more men as POWs IN A SINGLE ENGAGEMENT than we lost as casualties in the whole war.
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Literally 2 days before that above battle concludes the battle of Białystok–Minsk kicks off, thats another quarter million captured, also 5k tanks just like that
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At the EXACT same time as that they lost half a million as POWs at Smolensk
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All this happened within the first 3 months of the fight with 2 of them happening in the first month, this is what I mean by Russians ability to sacrifice is unparalleled. you could look at this and think "They should have got better at fighting and they wouldnt have had to lose so many men". Sure easy to armchair general 80 years removed, but do you realize how absurd it is they stayed in the fight after losing more than a million men as POWs in the first months? thats more men than most whole nations ever fielded and the USSR was just like

this was 1941! US boots on European beaches were 3 years out and you just lost a million men and the German army is about to overrun your industrial base but instead of quiting stalin calls up 5 million more men and order the factories packed up BRICK BY BRICK and shipped thousands of miles east into the Orel mountians and beyond.