How is it possible to have lower taxes and pay off the national debt?

If we paid off the national debt you could cut taxes in a major way. Now to do this it would take drastic change in government, I mean drastic. We would first off have to quit the wars over seas and pull all the troops home, except for a few carrier battle groups and submarines. Then all foreign aid would have to stop as well as any spending that is not absolutely necessary as we are $10 trillion in debt.

I believe the best thing that could be done was to change to a flat tax and everyone and everything pay around 20% with no deduction or tax breaks of any kind or even the fair tax, that I admit I haven't really looked at in its entirety. Also all subsudies would have to stop as we would need to return to true free enterprise. If we did this we could pay it and then taxes could be low from then on. But it would be drastic and everyone would have to learn to make it on their own, not to mention the foreign countries.

Just my opinion folks! Is it possible to do either of these things?