You know, the reality is that the WWII powers that *did* ratify the Geneva Convention adhered to it strictly. Germany, Japan, the USSR, and the USA never ratified it before the war, and that very fact that the USSR had never ratified was the excuse Germany used to wage its genocide against the Slavs.

And it hardly depopulated Europe, the USSR took the worst casualties of any European power and unless I'm mistaken the USSR was Europe's largest country by population even after the Russian Civil War, the Stalinist terror, and the Axis-Soviet War.....