> The reason Russia and China care so much about Ukraine and Taiwan, is because they worry having a functional democracy next door may destabilize their own reg

> The reason Russia and China care so much about Ukraine and Taiwan, is because they worry having a functional democracy next door may destabilize their own regimes. China cared about Taiwan when it was a authoritarian dictatorship for most of its history. I don't think it's a matter of government but a matter of lost territory. Using your logic, the north was worried about the functional democracy of the confederacy. Even if taiwan adopted communism, it wouldn't matter because it's a matter of territorial integrity. Meaning, it's just as lightly that we'd let south carolina secede than china would allow taiwan to leave. As for russia, considering that it's a democratic republic, I don't think they are too worried about that. What they are worried about is the geopolitical issues with ukraine - especially foreign interference in ukraine.