The situations in the US vs. the European nations that have been in serious trouble recently are barely comparable.

Even in the past year or so, with fears of further recession fading and growth returning to the PIIGS group, Greek unemployment is still running at over 27%, while the US is running at under 7%.

Similarly, while the US and elsewhere saw significant protests as part of the Occupy movement, they were mostly peaceful in nature. The violence seen on the streets of Greece around 2010-2012 as severe austerity measures were taken was on a different scale entirely.