For every creditor there must be a debtor, and these debits and credits have their counterparts in the current account deficits and surpluses of these countries. For every net exporter there has to be a net importer.
As Martin Wolf has recently reminded us, since the world cannot trade with Mars, creditors are joined at the hip to debtors, and any adjustment cannot be one-sided. These developments in the euro area have important lessons for other single currency areas, including moves towards monetary integration in Africa.