Reading a lib history book which mentions the Korean war a bit. One thing that stood out was the discussion about why the US decided to intervene when the North Korean forces captured most of the country. At that point they effectively ended the mass slaughter, mass executions, mass torture, mass incarceration and expropriation of communists and communist adjacent or even non ideological nationalist capitalists.
The South under Rhee literally killed families and people who were doing “free speech” bits. Another example is that a head of one prison forced anti communist tattoos on the whole population (which might’ve inspired the Inglorious bastards marking), those who resisted were beaten and tortured and the communist leader within the prison was put onto a platform and his arms would be cut of, he was mangled and executed - without any sentence - with a knife by the anti-communist Rhee approved prison head.
We aren’t speaking about “single cases” with those executions in the South either. However the thing I did really want to mention is this: The US intervened at a time that there were going genocides going on against others and the Apartheid laws were enshrined in legislation within South Africa, that didn’t lead to any political action from the sides of the US. They did chose to act “morally” and anti communist cause they didn’t want to have a strong communist nation next to freshly communist China. Their goal was driven by Kennan, racist and antisemite Truman and others and was controlling competed borders even if they had to kill every living being in them. The US did plan to attack China and Korea with nuclear weapons to (quote) “tame” them even.