What would mess this superpower up

What would it take for a superpower to be defeated? How should an attack go down that would pull a victory against a superpower?

If Russia and/or China was smart all they'd have to do is somehow sneak in a few non-nuclear Father of all bombs warheads (from Russia with love) and/or whatever other non nuclear warheads (from communist China) in on some ship port in Mexico and then have the shipped contianers trucked to targets in this here superpower. No radiation means it wont be detected at the boarder. Have them trucks park right outside certain main targets (like the White House, Congress; CIA, FBI, and U.S. Justice Department headquarters, Wall Street, and etc.) here in this superpower and detinate 'em all in some sort of sequence or all at once. Then it would all be over. This superpower wouldnt know who did what right away so they woud not retaliate unless they dare do it blindly. All Russia and/or China would have to do prior is set up their own trucking company there in mexico and here in the U.S. And moblize their own military and government incase of retaliation from the U.S.

I should be a general because I got the brain to train a whole nation.

The U.S. got a nasty habbit of waiting for somebody to step forth to claim they did it. I wonder what would have happened if Osama never stood up to take credit for 9/11??? Prolly the U.S. would have assumed it was Saddam involved.