That's why it's a great tradeoff. The US can have its "precedent" victories. Sure China will act mad and pay lip service to US patrols. All the while, China will continue to build up its hard power in the area. The US saves face and China develops airfields that can host assets that can cover the entirety of its claims (as well as hold the territories of all other claimants at risk). At any rate, I don't see anything short of WW3 causing China to give. Brilliant move on China's part, IMO.