It's posturing. They don't actually care one way or another about Taiwan or Tibet. The problem is that if they let it happen it shows the rest of the country

It's posturing. They don't actually care one way or another about Taiwan or Tibet. The problem is that if they let it happen it shows the rest of the country that they're able to get out if they choose to do so. Try to think of China more like the EU and Taiwan as Greece or Britain.