Same how the west also didn't care, that after WW2, the USSR occupied all of Eastern Europe, or that before that, Hitler occupied Austria and Sudetenland in Czechoslovakia.
Seems like there's a historically repeating pattern here where the amount of warmongering and territorial occupation you can get away with is directly proportional to to your military force and inversely proportional to the willingness of other states to go to war with you as the occupier. Just like how the US and its coalition got away scot free after bombing the shit out of Vietnam, the middle east and destabilizing North Africa. All we could do is "condemn it" and take in refugees.
I would also add economic power and ability to inflict painful sanctions to the equation. But were you really expecting anything else? This is how it always worked and the only thing that prevents hot global scale conflicts now I think is the threat of MAD.