The simple fact that countries like Greece and Portugal cannot adjust their exchange rates under the existing euro currency arrangement remains a critical problem says Krugman. Krugman points out that till 2007 Greece's budget deficit was no higher than America's as ashare of GDP than the deficits America ran in the 1980's, and Spain actually ran a surplus. The global financial crisis changed all that as inflows of capital dried up, revenues plunged and deficits jumped. Now membership in the euro area becomes a sort of trap in that Greek costs which rose quickly in the boom years now need to come down in relation to German costs, and the only feasible way of doing that would be to devalue the Greek currency, now impossible under the euro currency arrangement. The euro currency he says is in serious danger unless forceful action is taken to avoid a chain reaction that starts with a Greek default.