To re-hash and expand on some of the points made:
With satellite technology as good as it is, and with SOSUS and other technical intellgence gathering assets in place, a sucker-punch by the PRC aimed at forcing us to the bargaining table is just not conceivable. If there was an A-Sat attack, and a corresponding cyber-attack on our C3I, that in itself would set our spidey-sensing all a'tingling, looking for the other shoe (or bomb) to drop. Trying to imagine the PRC attempting a coup de main attack against Western (or Japanese) territory just exceeds the scope of my imagination. The PRC doesn't have sealift or blue-water capability to sustain and protect it against the USN.
Why? What would the PRC gain? They don't want our land, or our resources, they want our money. As fast as we're shoveling it over to them, why would they intervene? With the balance of trade they run with us, they can buy anything they want, oil, metals, intellectual property, anything, and pay for it with USD.
All that said, the reverse is certainly not true. If it was in our absolutely vital national interest, we could raise the U.S. flag on any spot on Earth. We may not be able to keep it there forever, but there are no forces on the planet that can withstand a determined assault by us.