Just a reminder, that debt was incurred by W, the War Criminal who instigated and prosecuted an illegal and immoral off the books war and tried to buy off seniors with an unfunded Medicare benefit. Obama added all of that, properly, to federal debt calculations.
And, please, in your bleatings about debt, feel free to credit the right wing for hobbling it with its idiotic opposition to a properly funded federal government and the largest military in human, and possibly galactic, history regardless of need or usefulness.
You want to reduce the debt? Reduce the size and scope of the military first. In the meantime, the U.S. is still the reference currency for the world and attracts investment because of the security it represents. No nation that buy U.S. debt does so to call it before maturity.