What it isn’t is a “debt our children will owe.” Foreign ownership of the debt is a small fragment of the overall debt total, the bulk of the debt belongs to Americans (i.e. us). Professor Krugman explains:
People think of debt’s role in the economy as if it were the same as what debt means for an individual: there’s a lot of money you have to pay to someone else. But that’s all wrong; the debt we create is basically money we owe to ourselves, and the burden it imposes does not involve a real transfer of resources.
That’s not to say that high debt can’t cause problems — it certainly can. But these are problems of distribution and incentives, not the burden of debt as is commonly understood. And as Dean [Baker] says, talking about leaving a burden to our children is especially nonsensical; what we are leaving behind is promises that some of our children will pay money to other children, which is a very different kettle of fish.
This is another example of what happens when you attempt to conflate macroeconomics with balancing your checkbook and paying your bills. There are a different set of rules in the macroeconomy. As the MMT crowd are fond of pointing out, if a government has a sovereign fiat currency (like the dollar, but not like the Euro), all it needs to do is print more money to pay it’s debts. And no, that won’t cause inflation (look at QE and QE2 which greatly increased the size of the M2 money supply without a trace of inflation).