The defense budget is driven in part by excessive costs for this and that, but it’s primarily driven by the fact that the United States has a very ambitious national security strategy for itself. Rather than try to focus on credibly deterring a major power attack on US territory while maintaining the capacity to intervene military in North America, we try to focus on credibly deterring attacks on the US and Western Europe and Japan and Australia while maintaining the capacity to intervene militarily anywhere in the world. That’s an expensive mission.
As it happens, it’s also a mission I would favor changing, so I’m not too torn up about the idea of the debt ceiling “trigger” being pulled and enacting steep defense cuts.
But it is worth pointing out that this is a pretty insane way to make national security policy. The Defense Department deserves to be given a relatively clear strategic mission from the nation’s political leaders and deserves a budget that’s consistent with that mission. If we want to change the mission, then that should change the budget. And the cost of a given mission ought to be a relevant consideration in whether or not it’s one we should adopt. But what we’re on track to do right now is fundamentally backwards. Rather than debating strategy and budgeting accordingly, we’re going to lead with a budget debate in which we may or may not enact a substantial cut in the defense budget based on whether or not a loosely related disagreement about taxes gets resolved. As I say, I’m not too heartbroken about it since I’d be all for these defense cuts whether or not as part of a deal. But it’s a mighty strange way to run the mightiest empire the world has ever known.