USSR controlled more land space than China and many more...

USSR controlled more land space than China and many more countries in the Eastern block and that fell.
Give it time. People do rise up if they get angry enough.

It nearly happened last year in Russia when a general of that group that decided to go after Putin but backed down
and that leader later died in a plane crash.

Putin reign will end badly for him and his cronies.
China will eventually have democracy.

US reign might come to an end too if Trump gets in. I see a world in kaos.
NATO will collapse. Ukraine loses the war.

Russia arming itself for future wars.