Douthat has a sane response to Kristol:
America’s military edge won’t be sustainable at all if we go bankrupt, lurch from debt crisis to debt crisis, or get stuck in a debt-driven economic stagnation for years or decades on end. And the Brooks-Feulner-Kristol argument for leaving defense spending untouched (“defense spending has increased at a much lower rate than domestic spending in recent years,” they write, “and is not the cause of soaring deficits …”) sometimes resembles the slightly-evasive arguments liberals use for ring-fencing Social Security spending that it isn’t the biggest chunk of the long-term deficit, that it’s projected to claim close to the same share of G.D.P. over the next few decades while Medicare spending explodes, etc. These arguments aren’t wrong, exactly, but they’re both ways of dodging the reality of just how big a share of our budget the outlays being defended really claim.