LOL. I love the concept. And if modified somehow along the lines Marik suggests (greater income = a greater share of the cost) I would support it. Especially if you levied the tax on corporations as well (they would pay a much larger portion, of course, than the average citizen). After all, many would argue that America's imperialist ventures are undertaken for the benefit of corporate interests, so why shouldn't they pay?
It would never work, but I love the idea.
We're putting the entire war on our credit card, yes, and our culture has become so short-sighted financially that this seems like an acceptable option. We do it in our own lives, so why not on the macro scale? Wheeee.