Yes, the common defense. Standing armies, however, I believe is an entirely different story. Not only is such a military industrial complex not conferred in the constitution but many will say that it's against the spirit of the Constitution and the Declaration of Independence in the first place. Having a huge military apparatus that occupies military bases in most of the world's recognized nations was never apart of the inclinations of the authors of the Constitution. I believe Hev was merely talking about returning to our more humble military existence we enjoyed before, at least so that we're not on the level as to where we're exporting our hegemony (*cough* I mean freedom *cough*) as an imperialist power.

Perhaps if the tax went to more social and humanitarian causes, such as feeding the poor, aiding the sick, or bettering our education system; the tax system wouldn't look as if to be a necessary evil.