Sometimes I write a post where I don’t know the topic well enough to discuss it expertly but I understand it enough to point to the outlines of the debate and where to find more information. This is one of those posts. Here, I want to discuss drones and missiles deployed by Iran and the expensive, high-tech weapons the U.S. and its allies use to shoot them down. This applies right now in the Persian Gulf where Iran is using a strategy of “asymmetric attrition.” But it would apply in even more complicated and hard-to-address ways if and when the U.S. got into a major conflict with, say, China over Taiwan. It’s that basic challenge of asymmetric warfare for a Great Power like the United States: the U.S. relies on often quite effective but very expensive and hard to replace weaponry. Iran’s clunky but effective drones cost in the low five-figures to produce, while U.S. missile defense tech can costs millions for a single shot.
As this article in SpyTalk explains, Iran’s missile capacity, which provided a key part of its deterrence, has largely come up empty in this conflict. That was even more the case last year when Israel shattered Iran’s air defenses and bombed the country almost at will, while Iran was barely able to damage Israel. A mix of U.S. and Israeli made defensive weaponry were able to drastically limit Iran’s ability to strike Israel. Head to head, these anti-missile and anti-drone systems and munitions are stunningly effective.
But there’s another layer of the story. Iran can produce its signature Shahed-136 drones rapidly and seemingly without limit, or at least it could pre-war. Those cost about $20,000 a piece. The Patriot and SM-6 interceptors the U.S. and its Gulf allies often need to use to intercept them cost in the millions. (Here’s a Times piece on this price asymmetry.) Cost is one thing. Presumably, when it’s important, the U.S. can spend a lot. We’re rich and usually vastly richer and with a bigger tax base than almost any country we go to war with. But it’s not just cost. These high-tech weapons take time to make and they rely on rare earth metals and other scarce supplies that the U.S, doesn’t entirely control. This is a question I want to learn more about. But I’m routinely surprised at how quickly the U.S. appears to run low on these kinds of munitions whether it’s in direct combat with Iran or as a supplier to countries like Ukraine.
“Run low” can obviously mean a lot of things. The U.S. has moved on from its longtime “two war doctrine,” being capable of winning two major regional conflicts simultaneously. But “low” probably seldom means you’re out. It means you’re getting low when you take into account levels needed to fight various potential conflicts the Pentagon wants to be ready for at all times. Of course the Pentagon is going to be vague about anything like this because just how much reserves it has is a pretty critical state secret. You want to keep potential adversaries guessing. But it doesn’t seem like it’s just shortages in the supplies that aren’t needed for other contingencies. The U.S. military seems to run into supply constraints pretty quickly. More important, the U.S. doesn’t seem to have the industrial capacity to produce these weapons as quickly as they’re likely to be expended in a drawn out major power conflict.
That issue of speed of replenishment is critical, in a way more critical than the size of the stockpiles. If we got into a major conflict with China over Taiwan and it went on for a long time, the U.S. doesn’t appear to have an industrial capacity to resupply these weapons on an ongoing basis. An additional factor is that all these high-tech weapons require rare earth metals for their production, a critical resource that China dominates globally. In a wartime situation, the U.S. would likely claim all the rare earth materials being used for civilian purposes in supply chains it controls. And maybe that would be enough. But it’s a real vulnerability, and it puts time limits on the U.S.’s military dominance. You can have military dominance. But if a critical part of that dominance only last weeks or months, that’s a problem. For now, it seems clear to experts that Iran’s strategy is to absorb the punishment from the skies and keep sending waves of drones into neighboring counties until the U.S. stockpiles are run dry.
Here’s a (likely paywalled) article in Foreign Policy which looks how many munitions, drones and interceptors each side is using, the cost and how simple or hard they are to replenish in real time.
Needless to say, Pentagon planners have given these matters a lot of thought. I’m not saying anything that people who work in these areas don’t know. But it’s a basic question that looms over any conflict like this and whether a lower tech, perhaps less wealthy adversary could grind the U.S. down in a battle of attrition we’re not — in industrial terms — prepared for.