What if countries with huge debts refuse to pay them?

Throughout history, many countries have refused to pay their external debts, and some of them even on more than one occasion. It is a situation that usually occurs at critical times: wars, natural disasters, deep economic crises, etc. But also, in some cases, non-payment is due to political or institutional motives: it is done by governments that have a discourse against capitalism or the market. In these countries there is often great legal unc…