What they simply have to do is dominate the region and Vietnam would have no recourse. In the end China will place it's oil rigs, Vietnam will take a token payment and China will get a secure supply of oil to fuel its’ military and industrial complex. Vietnam has no desire to be destroyed again this century. They are finally waking from the nightmare of the mid to late Twentieth Century that saw a massive percentage of their population decimated for the desire of nationalism.
All the while we will be setting up windmills and buying crappy solar panels from the same Chinese, while we sit on soil so loaded with oil and natural gas that a walk on the Beech at Malibu leaves tar on your feet as the oil naturally leaches into the ocean. All for the benefit of idiot environmentalist organizations controlled and run by Leftist morons.
That's what nukes are for.