Sorry if the topic is diverging too much, but:
Tell that to Poles, (former) Czechoslovaks, Estonians, Lithuanians, Latvians, (former) East-Germans, Romanians and other systematically opressed nations who fell behind the Iron Curtain.
The Soviets
started on the same side as the Germans, both invaded Poland in 1939. Even during the war the Eastern Front was a brutally nasty affair for all sides. Soviets aren't famous for taking prisoners, let alone for their treatment of them. There are numerous reports of Soviet fighter-aircraft shooting up opposing pilots stuck in their parachutes who had managed to bail from their aircraft. Soviet troops had a horrible reputation as "liberators" compared to the Western Allies (much more raping, reprisal-killing and looting going on). This is without bringing up the massacres such as the one in Katyn, or other ethically debatable events such as the sinking of the
Steuben.
To take a somewhat personal example: one of my grandmothers would probably have been summarily executed (or worse) had her station been overrun by the Soviets during the war.
Why? She was just an unarmed non-combatant radio-operator near the frontline.
Because she had volunteered for auxiliary service and therefore belonged to a specific
organisation that the Soviets had pretty arbitrarily deemed "fascist".
War is nasty.
If it breaks, you get to keep both pieces.