> Then why don’t the people rise up against their state?
Because the governments have taken away or undermined all ability for people to organize. When you have to fear every single friend of you being a potential informant of the Secret Service, how will you find someone willing to do anything that goes against the government? Rule by fear is incredibly effective, it was what held together the Soviet Union, Yugoslavia, the GDR and modern Russia and China.
> Why would it be the business of other nations to intervene in the internal affairs of another?
Because we as humanity should have learned something from what my ancestors did in 1933-1945 - namely, to not stand aside in the face of obvious inhumanity.