If Japan can survive for 30 years, it's dead, and the vast amount of post-doc number wanking justifications for every single crisis are pathetic.
Japan is able to run those high dept-to-GDP number because, by suppressing all other financial investment mechanisms in its' economy, it has deemed dept as one of the most profitable places for a Japanese person to park their savings accounts. They have essentially tied dept to savings. They are buying their own dept like crazy and finance their government expenditures that way but at the cost of increased inflation. The reason that they can still get away with it, is because they have some of the biggest car and tech industries in the world. But they haven't grown in decades, their country is literally dying (one of the 3-4 worst birthrates on the planet), , they are one of the most depressed countries in the world and their debt keeps rising. Where will this end? Should they let the dept go to 700%? What happens when their actual economic engine (their industry) slows down? Presenting Japan as the model for your theory is not the win you think it is...
Oh so the Communist Manifesto is political now? Fucking commies turning everything into politics.