I don't think they will right now. How could they? They don't have the tools and there's too much support the opposite direction. But what about 10 years from now when China is more integrated into some of the developing world that will be middle-class by then? They will be hard to sanction and their military Will be significantly ahead of where it is now.
Same thinking ? Just too expensive of a cost?
Oh yeah, 10 years from now Taiwan could be fucked. But probably more like 20.
The US' only - but it is a big only - has a technology advantage in a war over Taiwan. But if China can make further inroads in that department, then with heavy manpower, manufacturing capacity, proximity and willpower advantages, the US wouldn't stand a chance of defending the island in a conventional conflict. Some say it would even lose now, but I agree with others that China can't now.
My guess is that if it ever gets to a point of impending invasion, it won't actually happen. Taiwan and the US will realize that the odds by that point are too overwhelming and nuclear war isn't worth it either. Taiwan probably accepts a Hong Kong-like 'two systems' deal.