Outside the Beltway

The Logistics of Massive Air Defense

Shooting down cheap drones with expensive missiles is problematic in more ways than one.

James Joyner · Monday, March 2, 2026 · 11 comments

In their WSJ report, “U.S. Races to Accomplish Iran Mission Before Munitions Run Out,” Michael R. Gordon and Shelby Holliday lay out the titular problem facing American forces:

When the U.S. military’s top general laid out the risks to President Trump of launching a major and extended attack on Iran, one of the issues he flagged was America’s stockpile of munitions.

Now that is being put to the test, as the U.S. races to destroy Iran’s missile and drone force before it runs out of interceptors to fend off Tehran’s retaliation, current and former officials and analysts say.

The precise size of the U.S. stock of air-defense interceptors—what the Pentagon calls magazine depth—is classified. But repeated conflicts with Iran and its proxies in the Middle East have been eating into the supply of air defenses in the region.

[…]

“One of the challenges is you can deplete these really quickly,” said Kelly Grieco, a senior fellow at the Stimson Center think tank who used to teach at the Air Command and Staff College. “We’re using them faster than we can replace them.” 

The Thaad antimissile system was deployed to Israel in 2024, along with the U.S. Army troops to operate it, as the Biden administration sought to protect the country against Iran. A Thaad has also been deployed to Jordan, where many U.S. combat aircraft are now deployed. A major concern for the Pentagon is to maintain a sufficient stock of interceptors for the Thaad, which U.S. forces also operate in South Korea and Guam, to deter North Korea and China.

The Pentagon is also racing to replenish stocks of Patriot and Standard Missile interceptors, which also take out aerial threats and are being used to defend against Iranian missiles and drones. Patriots take out lower-flying threats, while SM-3s can intercept ballistic missiles above the Earth’s atmosphere.

Air-defense interceptors aren’t the only munitions that are in short supply. The U.S. is also expending sea-launched Tomahawk cruise missiles, widely known as TLAMs, and aircraft-launched weapons against Iranian targets. This comes on the heels of Operation Rough Rider, the U.S. campaign last year when the U.S. used long-range precision weapons against Yemen-based Houthi militants.

There’s quite a bit more to the report, but you get the idea.

Grieco has a thread on the platform formerly known as Twitter detailing the problem. BLUF: it’s not just magazine depth, but comparative cost. I’ve cleaned it up a bit below:

UAE is shooting down ~92% of everything Iran throws at it. That’s extraordinary. Yet the financial toll of sustaining that defense is enormous, raising the prospect that tactical ‘victory’ masks a costly strategic drain.

Since Feb 28, Iran has fired at the UAE: 165 ballistic missiles, 2 cruise missiles, [and] 541 drones. UAE knocked down 152 missiles, both cruise missiles, and 506 drones. A 92%+ intercept rate.

But let’s talk about what that actually costs.

Iran’s bill (estimated):

*165 ballistic missiles @ $1–2M each → ~$165–330M
*541 Shahed drones @ $20–50K each → ~$11–27M
*2 cruise missiles → ~$1.5M

Iran’s total outlay: ~$177M–$360M

Now the UAE’s side. Each PAC-3 MSE interceptor costs ~$4–5M. Assuming a two-shot doctrine to ensure a kill, 152 ballistic missile intercepts × 2 shots × $4–5M = ~$1.2B–$1.52B To counter ~$165–330M worth of missiles.

The drones are where it gets truly punishing.

Iran spent ~$11–27M on 541 Shahed drones. The UAE fired interceptors averaging $500K–$1.5M per drone kill against 506 of them. UAE drone defense cost: ~$253M–$759M.

UAE spent:

*Ballistic missile defense: ~$1.2–1.52B
*Drone defense: ~$253–759M
*Total: ~$1.45–2.28B

The UAE spent 5–10x more defending than Iran spent attacking.

The drone ratio is the sharpest edge of this problem.

For every $1 Iran spent on drones, the UAE spent roughly $20–28 shooting them down.

This is the core of Iran’s strategy — and it’s not new. It’s the same math Russia has been running against Ukraine for 3 years.

To be clear: the UAE had to intercept. But here’s the strategic trap: every interceptor fired is one that can’t be replaced overnight. PAC-3 MSEs take years to manufacture. Iran’s Shaheds do not.

The UAE has now burned through a significant chunk of an interceptor stockpile that took years to build — in 48 hours.

There’s more but those are the key takeaways. As Economist Middle East correspondent Gregg Carlstrom pithily summarizes, “using Ferraris to intercept e-bikes gets expensive fast.” And Ferraris are much harder to replace.

This, to be sure, is simply the nature of modern war. Defending from aerial attack is getting more expensive, while attacking from the air is getting cheaper.

From a pure cost perspective, the United States, Israel, and regional partners can absorb this. Iran’s economy is devastated by years of sanctions. But it’s quite possible that we’ll run out of exquisite munitions before they run out of cheap and easy-to-replace drones.

And, of course, China is ostensibly the United States’ pacing threat. Our ability to deter their aggression against American allies and interests will be significantly weakened by this drain on our stockpiles.

A few days back (i.e., even before this war kicked off), Christian Brose pointed out what many have been saying for years: “America Needs a Lot More Weapons.”

In a conflict with China, the U.S. would run out of critical munitions in days, according to the results of war games. Recent events strengthen the case for weapons inventory. Ukraine expended a decade’s worth of U.S.-produced antitank and antiaircraft weapons in months of combat against Russia in 2022. In a few days of air-defense operations against Iran last year, the U.S. fired one-fourth of its Terminal High-Altitude Area Defense missiles—billions of dollars of weapons that took years to produce.

[…]

The common refrain is that Washington has underinvested in weapons, and there is truth to this. Over a decade ago, as staff director of the Senate Armed Services Committee, I pressed Obama administration officials on why their budget requests always shortchanged munitions. Not to worry, they argued: Limited resources were better spent on slow-to-produce ships, aircraft and other platforms; in a crisis, the U.S. could rapidly build more weapons.

Congress disagreed and increased budgets for weapons. Since fiscal 2015, annual spending on missiles and munitions has more than tripled. The bigger problem is this increased spending, insufficient to begin with, hasn’t led to commensurate increases in production.

[…]

Our critical munitions were conceived decades ago when many assumed the U.S. could win any war so quickly that we’d never have to expend and regenerate large numbers of weapons through ramped-up production for months or years. Government and industry optimized our weapons to be ever more exquisite, expensive and scarce. They became the military equivalent of luxury goods—their production constrained by rare materials, specialized labor, artisanal manufacturing, bespoke components, noncommercial supply chains and other limitations. This is a self-inflicted shortage of military power.

The Trump administration can be commended for trying to expand production, but money alone won’t solve this problem. We need new and different weapons that are simpler, faster and cheaper to produce. They should be designed to be made in great numbers and by the largest possible workforce, using commercial manufacturing practices and supply chains.

Our weapons have become overly complex, seeking to meet every requirement within a single munition, which leads to weapons that are effectively unproducible and irreplaceable. We need a high-low mix: smaller numbers of exquisite, expensive weapons for our smaller numbers of high-end threats, alongside a more affordable, more producible class of weapons for our larger number of lower-end threats.

He’s right.