Using Japan as a bad example for excessive public debt is like using Denmark to illustrate the dangers of excessive socialism. Yes, each would be better off without that foible, but they have so much else going for them that they do well nonetheless. They are smart, disciplined, and culturally homogeneous. It's hard to prove the stupidity in question because otherwise they have their shit together. Conversely, decent living standards, high educational achievement, and low crime in these places are not proof that the US should become more socialist or that the government should take on more debt.