I don't think anything is going to come of this anyway, just more hot air.I'm sure they are getting sick of them, but there's still a matter of saving face geopolitically. North Korea is the only thing keeping our troops off of their border, which is also something they don't want. Russia also. Unless we had assurances from the Chinese and the Russians that they weren't going to jump into the fray, I'd be very wary of doing anything preemptive.
I don't think we would go to war about it.Picture if the Chinese invaded Mexico. No matter our feelings about the Mexican government, having Chinese troops across the street from San Diego (which Tijuana is) would be very bad for us.