I would not be quick to say that we do not have enough prepositioned ships to make a good start. The locations of carrier task forces or our current shortage of them is pretty well known and crippling. I would not, however, discount the possibility of American attack subs in the area or underestimate their effectiveness against Chinese warships. The Marine base on Okinawa also has admirable anti-aircraft capabilities, especially short range using FLIR systems. Would it be enough to wage an all-out war with China? No, but it might be enough to hold the fort until the cavalry arrived, especially if combined with B2 strikes on Chinese command and control from Whiteman AFB.

I do think that such an encounter would eventually go nuke though. If China makes a play for Japan or Taiwan I do not think they will give up without pushing the button and hoping the fallout will take out the US by following the same path as the fallout from the damaged reactor in Japan. A limited nuclear strike on Japan by China would hit us with fallout, and if we in turn nuked China we would get even more fallout.

I think a much more likely scenario would be for China to launch camouflaged commercial rockets into orbit with nuclear warheads tuned to max EMP, allow them to drift in orbit toward us and take out the US power grid from space keeping our forces here busy and causing us to pull back our forces from the rest of the world. Once we have left the area to nurse our wounds Japan, Korea, and Taiwan would be ripe for the picking using the American “Shock and Awe” tactic coupled with invasion.

Just speculation on my part…

I used the wrong phraseology. Didn't mean we would not, I meant Could not. We no longer have the prepositioned ships and troops to do the job. Same with Russia. Not sure what they could do if they wished.
India, if they wished could come across the Himalayas and then east.
Just not sure what anybody could do short of going nuc. That's the problem with the big boys Not much a anyway to stop them except nuc and they have them too.
A Bloody Awful Mess..

We have a pact with Japan (Treaty of Mutual Cooperation and Security) saying that if they are attacked we will go to war for their defense. It is a legally binding defense contract and the price Japan paid for its aggression in WWII. They are allowed under the terms of the contract to keep only a military force necessary for self-defense. The pact also covers the disputed Senkaku Islands as of 2012.

Given our current political climate that does not mean that the US president will not issue an executive order to “chicken out” of the whole deal.

The agreement is also null and void if China is able to provoke Japan into firing the first shot.

Assuming China fires first, and our president does not abandon our national commitments, an attack on Japan by China would constitute WWIII.