Greece's and other southern European countries' debt has been considered a problem since the 2008 crash, and austerity measures have been forced to the people.

However the United States also have a colossal debt, yet I have never heard of it being a problem or that the United States requires austerity measures.

I have no idea how accurate they are, but the [US debt clock](http://www.usdebtclock.org/) displays a debt with 14 significant numbers in US$, while the [Greece debt clock](http://www.nationaldebtclocks.org/debtclock/greece) "only" displays a debt with 12 significant numbers (also in US$).

I know that the population of Greece is much less than in the U.S., however I do not think it matters to people "lending" money to the governments - *In both cases it seems extremely unlikely that this money will ever be refunded.* Also Greece receives more tourists each year than it's own resident population (15 million tourists for 11 million residents) so it's hard to compare.