Yes demographic shift and bubble economics, this much is true. But Japan is hampered by constitutional restraint of their armed forces, the United States economy (infamously) enjoys much broader support from intelligence and military. Japan also historically rejects mass immigration, which the United States has adopted as a means to replenish low skill workforce and 2nd generation child->skilled worker pipeline. If political power can successfully be wrested from the boomers, the USA can abandon their entitlements and rebound quickly. If boomers hang on to political power: a period of sticky inflation and slow growth.

Boomers? Sigh. Please articulate better. You can't refer to an entire generation as 'at fault'.

It's dumb, greedy, selfish politicians, and they come from all generations, including yours and mine, and in the future they'll come from generations not yet old enough to run.

Boomers is a stupid term used by people who only understand easy answers.