maybe a better examples are proxy wars like the Congo and Vietnam in the 60s or Syria or currently Yemen than Crimea considering most in Eastern Crimea had greater allegiance to Russia from the start .
In a proxy war both sides used a sacrificial country to push their own agendas, given China's disinformation programs in Philippines would not be surprised if they continued to try to built up a political influence there , fortunately from family members I am informed there is considerable hatred towards the Chinese govt by the Philippine populous, so has been a failed exercise to date .
Other Islands in the Pacific may be easier bait ie Solomons or PNG where the population are of generally low intelligence and easily manipulated with bribes or good deals even the supposed intellectual coalition gave the East arm port of Darwin to China for 100 years so there is precedence.
I doubt China would go the nuclear route, as much as their govt are cruel and cunning they are a highly intelligent people who know the repercussions of nuclear warfare for all and what point is nuking a country when you can not profit from the spoils ?
