Does the national debt have to be paid off at some time in the future? What will happen if it is not?

What factors determine whether the national debt is a cause for immediate concern?

Which of the following owns the largest proportion of the national debt?   a.  foreigners   b.  federal, state, and local governments and the Federal Reserve   c.  private individuals, banks, and corporations   d.  foreign governments

if you were the leader of a country and you had control of fiscal and monetary policies, what would you likely do with the use of fiscal and monetary policies before the next general election?