Facepalm

Whether you believe Ukraine belongs to Russia or not is immaterial. Russia the imperialist capitalist state, which is what replaced the Soviet Union that America worked to destabilize until it collapsed, has nukes, Ukraine does not. The ending was decided before the conflict started.

Taiwan is what remains of the old Republic of China that was mostly overtaken by the PRC. It also does not have nukes, but it does have sensitive chip manufacturing equipment. The politics of the island are divided.

Ethnic conflict in former Yugoslavia began when the Soviet Union collapsed. Do with that what you will.

South Korea was upheld by a series of brutal capitalist militarist dictatorships installed by the USA after its formation. It is part of a nuclear armed military alliance. Democracy is still relatively new there.