The fact that Greece didn't meet the required criteria was well known at the time. The decision to let Greece (and others) join the union was a political one.

The fact that Greece didn't meet the required criteria was well known at the time. The decision to let Greece (and others) join the union was a political one. I think the larger countries reasoned a country so small could only have a tiny effect on the overall economic picture. It's true, too - the Germans and the French have enough money pay Greece's bills indefinitely were they willing to do so. The Achilles heel of the EMU was always that monetary policy is controlled in Brussels and each country has its own fiscal policy. While the individual countries are supposed follow certain fiscal rules there's no real enforcement mechanism. In the long run that can't work. Either we're going to see a United States of Europe with both fiscal and monetary policy being set in Brussels, or the EMU is going to fall apart.