If you think China will take everything then, you had too much Western education, or have no real understanding of the political game. Vietnam and China are both old imperial powers, we know how this game is played.
If you answer the call, then you will die for a war that has no meaning, not because of being on the losing side, but for missing the point.
I'm pretty sure Vietnam government knows what the deal is, and I'm sure Vietnam knows the importance of ASEAN to China. Vietnam cannot agree this easily, it wants more of the pie, in the end this dispute will be over and Vietnam will be on China's side. There may be a battle, but there will be no war. Vietnam will come out of this more powerful than before.
But of course, you need to know what to look for. The game of politics is not as straight forward as taking a sea, there's tons of other factors to consider. Interests are never as limited as resources.