Why is Noone Talking About Japan Going Bankrupt?

The Japanese national debt is well over 200% of GDP, compared to the Greek national debt of 140% or so which forced them into bankruptcy. Japan can afford it for the moment but when interest rates go up Japan may be unable to afford to service its debt. Imagine a country going bankrupt for debts at about 30% of global GDP.
We’re all going to suffer for this.