Yep China is running a complete shell game and IMO it's not going to end well. There are so many zombie and shell companies getting free state money right now, and they're creating massive overcapacity and inventory, but all that can't go on forever (though it could go on a fair bit longer especially with their manipulated statistics hiding things). Bare minimum it should manifest in massive currency depreciation over the next decade.
In the longer-term, China's demographics are miserable, like a lot of countries, so their ratios of workers to retirees will go south on them soon, which will compound things. Decades of one-child didn't help there although politically and economically speaking they also didn't need a few hundred million more people running around either.
Japan will implode more quickly than China, though, IMO, or again at least their currency will likely heavily decay. Their mountain of government debt will never get repaid in the traditional sense of the word "repayment". Either the Japanese government will basically retire much of the debt (gov't buys its own bonds and never "requires" repayment or extends to crazy-long maturities), or, they'll repay it through currency that is worth a fraction of what it was worth when the bond was bought.
When you mix in a few other "lost cause" major country economies as well as countries with entirely too much debt and unfunded liabilities, it's unprecedented and super-risky. I'm not sure if there will be an endgame to all of this or if it will just manifest in decades of zero-growth and deflation. What I do believe is that this was perhaps the biggest case of intergenerational theft in world history, as trillions and trillions of dollars of demand and consumption simply got pulled from the future to the present/past. The younger generation got royally screwed here and have a right to be mad as hell.
