Obviously, the incessant debt expansion is not a sustainable economic model. Since 2009 the debt/GDP ratio has no longer been climbing. Adequately, the GDP growth has not been breathtaking, to put it mildly. In the Euro Area, the debt/GDP ratio declined by 8 per cent from 2009 to 2013. An economic stagnation has followed. (Would you expect anything else to happen?)
More data on the Heavily Indebted Rich Countries is here. Japan stands out from the crowd as the economy where a large scale debt crisis happened first.
The US economy is in a better shape, since the American domestic credit is mainly financed by bond issues rather than by bank credit. That's why the US banking crisis has been resolved much faster than that of Europe.
Also note that the so-called Heavily Indebted Poor Countries are not indebted at all!