Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

The U.S. National Debt: What is it, where did it come from, and how does it work?
For political reasons, almost all governments (including the US) spend more money than they get from taxes etc.  There are a number of things a government can do to cover the difference: Most governments opt for selling bonds.  The "National Debt" of a country can be thought of as being the sum of all the "Bonds" that are still paying interest, and that the Government hasn't Redeemed. It can all go horribly wrong.  If the Government gets into a situation where it cannot pay the interest, or it cannot Redeem the Bonds it has promised to, then it may have to break its promise ("Default" on its payments).  This makes the owners of the Bonds unhappy and means potential buyers of future Bond sales are less likely to want to buy the Governments new Bonds - effectively meaning the Government has to promise to pay more interest in the future.  Recent examples of this include Argentina; and may include Greece soon. The US is in the fortunate position that not many people believe it will Default.  Therefore the new Bonds it sells (which it does on a regular basis) are still in demand, even though its interest payments, and promises to Redeem Bonds are huge.