Because I can't see the US actually starting a real one.
But isn't it a shade hypocritical of the US to complain about the increase in the Chinese military budget, when, even at the US worst case guestimates it is still only a quarter of that spent by the US.
I'm inclined to think the problem is more that they will, eventually, no longer be the only player in the game in Asia........and they don't like the idea of not being the big cheese everywhere.