There is no true ally in this world. Vietnamese World is already the best example.
U.S. gave up South Vietnamese government and those South Vietnamese who trusted them.
U.S would surely give up his new ally if things turned bad again.
Don't forget the U.S is leaving afganistan now.
For China, the reason why China has no true ally other than the Pakistan is beacause China is not in advantage.
Why would China pick a fight or act aggressively now?
If you ask why China has problem with all of its neighours, I would say that it is because China is big but wasn't and isn't stronge enough.
There are many historical problems bettween China and its neighours.
Since China is not a superpower like USSR or USA, when there is a problem, nobody listens to anybody.
In all these year, no agreement of any kind are made on any of the issue, but at the same time, they all felt being bullied.
If you apply this to game theroy, then everyone wants to act like victim of aggressor and claim as if they are right on every problem.
If anyone wants to be rational, then this guy loses.
By the theorem, fallcy of composition, what is true of the parts of a whole may not be true of the whole. What is going on is going to triggers war sooner or later which we know isn't the best solution. No matter who wins, the result also isn't going to be just. The suffer at the ends fall on regular citzen like most of the people in this fourm. Cheers!
Yet, we are so happy here "defending" our country in a international communication base to make the tension worst. This is not how you want to show your love to your country. At the end, there is only human family and people in this planet, earth.
The best thing to do as I see is to shelve the disputes and leave all of these mess to the future generation when the rule of game is changed becuase of social and economic changes, so that people can act rationaly and really tries to solve problems.