Rottweiler - And when you provide a source for the $15 trillion figure, I'll be happy to answer it.
My "source" is 4 years of living under the Obama Administration. See, this is the problem with you as I have pointed out on many occasions now. You're over there in Europe with zero idea of what's going on in the United States, yet you comment on everything that you are uninformed on.
When Barack Obama took office, the national debt stood at $10 trillion (actually 9 and a whole lot of change, but I'll round up for simplicity). Today it stands at over $16 trillion. Now, he hasn't even been in office for 4 years, but again I'll round up for simplicity's sake. That comes to $6 trillion over 4 years or $1.5 trillion per year.
So, if you multiply $1.5 trillion by 10 (years) you get $15 trillion. It's a combination of knowing what is going on in this country and simple math. Now that you know the "source" and the facts, care to comment?