Europe has an interesting dynamic. Multiple countries share a currency. So if one country, especially a small one, decides to spend more than they have, the other, presumably more prudent countries, wind up paying for it.
In a single country with a single currency like the US, if we spend more than we have, we'll print money to cover it, and everybody in all the 50 states shares in the resulting inflation.
Europe has national deficit rules to prevent excess inflation of the euro, but they aren't followed very well. Everybody has the incentive to cheat.
Yikes! First Greece, then Portugal, and just now Spain!
A 2-year Greek bond yields 23%
John