Sure China's current military tech is very similar in capability to US mid 90's capability, while their submarine force is more akin to the 70's US sub fleet. We will keep China bottled up simply because if they really piss us off we maintain a massive advantage in firepower and their billion man army can't make it here, because we could torpedo every single transport, then launch ballistic missiles into Begin from the south China sea, and China knows this, and this capability isn't going anywhere, look at future US plans for our military. Directed energy weapons for shoot-down of incoming weapons faster which could render missiles obsolete as once they are deployed they will quickly spread to the rest of the fleet, meaning your gonna need to again fire slugs to sink ships which puts you in range of carrier aircraft, which likewise are operating generation 2 stealth fighters, china is very much behind on stealth technology, in that area they seem to be where America was in the 80's, and they seem to be prioritizing defensive capability over offensive, so don't expect major improvements in their stealth capability.
As for how we remain the number 1 power, what Rome didn't have, what England didn't have was the 2nd largest nuclear arsenal the world has ever known, and I would hope should a foreign power attempt to topple our power that we would unleash nuclear hell onto their country.