You need not just troops but replacements when they rotate out. Iran is 3 or 4 times the size of iraq, both in area and population. We have 160,000 troops in iraq, and not enough replacements to maintain even that beyond next spring. An invasion of iran would require a bare minimum of a a half million, and another half million to replace them, not counting those in iraq, afganistan, south korea. We don't have them without a draft. It's not the invasion that's the hard part, it the what then. Just tell them you're gay.