The Glass Ceiling

China will grow in power, in the following decades. Unless they fall apart, of course. But if China does continue to grow in power, they will eventually rival us in power.

But does this mean that China will become the dominant nation? Probably not:

But in any case one flawed assumption Jacques entertains is the idea that the rest of Asia will simply acquiesce to China’s emerging hegemony. While all the region seems to sense that they have little choice but to work with China and accept to some degree its growing economic and strategic footprint, there is something else afoot. Looking around China’s periphery, Japan, India, Indonesia, Vietnam, and Australia are all hedging against a Sino-centric future, bolstering ties to the U.S. and strongly encouraging U.S. deeper engagement in Asia. This is not any sort of “containment” but perhaps a sort of balancing. If China pursues a pattern of blatently aggressive, imperious behavior, these nations along China’s periphery could form the nucleus of a counter-weight.

Will China Rule the World? A bit of an overstatement. But looking out to 2050, viewing China as a dominant player in a multipolar world would not seem unrealistic.

Yes, China has inspired neighbors to arm up and reach out to us to help them balance China. As China gains offensive capabilities against their neighbors, their neighbors respond by developing capabilities that can be turned against China. Our power becomes more relevant to each under these circumstances.
 
And even if China matches us in power or even surpasses us, we will continue to have more free power to project far from our shores than China can ever muster given all the hostile or potentially hostile neighbors that pin China's power in place.

And this is worst case, as near as I can figure. Don't count us out in retaining the number one spot absolutely.