$20,000,000,000,000 (TWENTY TRILLION) in federal debt and you call it fun? What the hell is your background? Another do-nothing, federal employee that sucks the teat of the American taxpayer?
I see two options - 1. multipolar world, where USA can be first among the equals, or 2. bipolar world, where USA will dominate Europe and Latin America, while China will dominate Asia and Russia. (Africa will be zone of proxy conflicts)
I think that because bipolarity is the most common for all complex structures it the most likely.
Transformation might take couple decades, best if without major war.
It's over? Already? Oh well, it was fun while it lasted.
BTW, who's taking over world domination?
Islamic jihad. It has shown a remarkable resistance to change over fourteen hundred years and an uncanny abilility to feed off the weakness of other nations.