[jollybean]

Crimea has no value to anyone, it's a sparsely populated barely industrialized island and 1/2 the population is Russian anyhow.

I don't think there will be war over Taiwan, because if it was an effective Chinese invasion - there is nothing anyone could do about it. If China takes the Island, then they will keep it, not even the US could displace them without incredible force of power.

If the US was involved in the fight and US took casualties i.e. downed fighters/bombers, or worse, a ship sunk, then the US will extract blood for that in other ways, notably, I can see the US and allies pushing China out out of the S. China Sea as a form of retaliation because it's militarily plausible.

But it would take nuclear war for anyone to push China off of Taiwan if they secured it and were well dug in and nobody's going to do that.

[pphysch]

Crimea has significant (defensive) strategic value to Russia, not unlike Taiwan for China or Cuba for USA. They really don't want a hostile power putting missile silos or aircraft carriers there.