thanks for sharing your thoughts @patriamreminisci, yes you are right about undisputed power from the US, but what I'm saying at the end of my statement is:
If we go back in time, we see the evolution of geopolitics, handing power from Egypt, the vikings, ottoman empire, roman empire, so on and so forth until the US claim the power, in the end certainly, "the ones who's left are the ones who's right". - unknown
The geopolitic sphere of influence is constantly changing. If not China, it might be India or Russia. :)
Well, that's my point. There's not likely to be a central global authority, the way the world is shifting.
America's maneuvering right now is to make sure that when the dust settles, none of the other powers are near to her own backyard while still keeping at least a toehold in theirs.
Russia is going to do what they have always done: maintain a reality where, on one hand, even though their economy will not permit a prolonged war, they are capable of doing enough damage in a short one that no one is willing to fight them unless absolutely necessary, then on the other hand trying not to push other powers to the point where "absolutely necessary" is how they view sch a war.
China... well, they're trying to step up on a global scale and they're making a lot of major enemies really close to home right now, most notably India and Japan, and there's an entire alliance forming against them right inside their "Nine Dash Line." Meanwhile, Sri Lanka, Pakistan and the Maldives are all starting to balk at the price China's "gifts" have had as they watch their sovereignty being chipped away (or shredded outright in Pakistan's case). They are going to be fighting on six fronts if it comes to a war, and they are starting to wake up to that fact. They'll continue throwing their weight around for a little while, then they'll shift their tune and retreat while shrieking about the "Western Imperialism" that forced them to do so. No one abroad will buy this, but it'll be good enough for home consumption and generate domestic sympathy for the CCP (which is at an all-time low right now), and keep them in power.
People say I'm crazy for this, but I see Japan, rather than China, being the dominant power in East Asia by 2040. They already have a more powerful navy and air force than China (with A LOT more experience), and they're what's called a "nuclear threshold" nation. A nation which, despite not having a nuclear weapons program, has all of the prerequisite technology and scientific expertise to complete a nuclear weapon (or several nuclear weapons) in a matter of months if they decide to (and need I even mention that they are the world's undisputed leader in cyber-weaponry and AI, and running a dead heat with Israel for leadership in missile interception). Economically, everyone is so focused on China's OBOR right now that they seem not to notice Japan is already the leading investor in Southeast Asia (meaning a lot of countries can more readily piss off China than afford to piss off Japan), and after America pulled out of the TPP, they took it over and have been running with it. The Pacific Rim is, from an economic standpoint, a lot of Japanese satellite states right now.
The thing the U.S. is worried about is making sure that China's population, Russia's natural resources, and Central Europe's technological and economic infrastructure (and military experience) all stay separate from each other and none of those three succeeds at bringing one of the other two into their orbit. If that happened, all of Eurasia would be under the dominion of one major player and it would be a threat not just to our power but to our existence.
George Friedman (an intelligence analyst who has made some rather absurd predictions on a few occasions but has been right more often than he has been wrong) has an interesting list of who he thinks the four dominant players will be by 2050.
I won't say who, but it's interesting to note that neither China nor Russia is on the list, and the only Western power to make his list-of-four is the U.S.
Anyway, that's all speculation, but unless China manages some really slick diplomatic maneuvering in a short maneuvering window of the next few years, I see them crashing hard in the early 2020's. They're on the brink of war with more than 10 countries right now (12 if you count internal rebellions as countries), but there's not a single soldier in the PLA with an hour of heavy combat experience and China knows it. The next few years will be about how much they can grab before a "new normal" settles in.