I wish there was a viable alternative, but there really isn't, is there? Would we be having this discussion if there was? Of course not! The U.S. Government wouldn't get away with a 1/10th of the nonsense they get away with if there were a viable alternative, and we would have never gotten to this point.
What other non commu-dictator-led country taxes you on worldwide income as a citizen? Worse, what country can (and does) infringe on the sovereign rights of just about every civilized country on the planet in order to hunt down dissenters of this ridiculous policy?
So how does it unwind? It is going to take another sovereign (note, EU doesn't count) entity with a small, fiscally sound government, who is psychotic about personal property rights (think... Swiss... 30 years ago), strong and consistent rule of law, transparent free market economy, and a desire (and will to obtain, at whatever horrific human cost) for hegemony. Note that I didn't mention democracy in there.
For those pinning their hopes on China, my thoughts are it is going to take a civil war (with incumbents losing) followed by my recommended recipe for world economic powerhouse above for them to be a solution. Those who are real sinophiles will realize that this simply is not likely if for no other reason than that China for thousands of years has had no real interest in becoming a world superpower or being "Global Cop", which would be absolutely necessary in order to replace the US as you know it today.