Now there is a crisis, and the unsustainability of the public debt of country A is undeniable to everyone, so no-one will buy the bonds, well maybe for 5 EUR. However, through lobbying etc. a deal is struck so that Country B lends Country A 60 EUR to buy the bonds for the artificially high price of 53 EUR, thereby allowing the banks to escape the full writedown from 100 EUR to 5 EUR, but pushing 48 EUR of unrealized bankers loss onto the public books of Country A (debtor) and Country B (creditor).