America's interceptors will run out before Iran's missiles

The signs are piling up. American and Israeli planners have drawn up strikes on Iran for after the midterm elections on 3 November, according to the New York Times and ABC News; the White House says only that there will be no attack before then. The State Department has ordered staff out of Saudi Arabia. Two American aircraft carriers are in the Arabian Sea and a third is on its way. Iran keeps firing at tankers in the Strait of Hormuz, and in September it fired missiles at American warships. Our Iran war tracker puts the chance of American strikes on Iran within 90 days at about 73%, close to what betting markets say.

If the war of February to April 2026 resumes, most of the public argument will be about how many missiles Iran has left. That is the wrong number to watch. We compiled about 660 published figures on missiles, launchers and interceptors, rebuilt the 2026 war day by day in a model, and ran a new war forward from today. The answer turns on something else: how fast America and Israel can find and destroy the trucks that launch Iran's missiles.

Iran has missiles to spare

Estimates of Iran's arsenal seem to contradict each other. Israeli officials say Iran has 1,800-2,000 missiles able to reach Israel. American intelligence said in May that about 70% of Iran's pre-war stock had survived, which after 2,180 launches would imply many thousands. The two are counting different things. Israel counts medium-range missiles ready to fire. The American figure counts every class, including short-range missiles and those in tunnels that American strikes had sealed and Iran later dug out.

Put every published estimate into one account of missiles built, fired and buried, and they fit. Iran has about 1,750 long-range missiles ready to fire, and about 3,000 short-range ones that can reach the Gulf.

That is enough for a long war. In a two-month war starting now, Iran's long-range stock runs out in only about 3% of our simulations. Even whether Iran makes 100 new missiles a month or none makes almost no difference to how a war goes.

Launchers set the pace

What limits Iran is launchers. On the first day of the 2026 war it fired about 430 ballistic missiles; within a week it was firing 30 to 40 a day, and it kept to that pace until the ceasefire. Its missiles had not run out. Its launchers were being destroyed, or trapped in tunnels, and the crews that survived fired less often to avoid being spotted.

Our model of the 2026 war matches Iran's daily launches and the Israeli army's count of launchers still in action. It finds that American and Israeli strikes knocked out about 8% of Iran's working launchers a day in the first ten days, and about 2% a day after that. Without that hunting, Iran would have fired about 4,900 missiles instead of about 2,000. In the June 2025 war, which Israel fought largely alone, the rate was almost the same: about 9% a day.

The rate depends on finding launchers in the few minutes they are out in the open, which is mostly done by drones circling over Iran. It does not rise with the number of bombs dropped: in 2026 about 300 launchers were claimed in the first four days, and only about 35 more in the next 20, despite thousands more strikes. America has lost about 45 Reaper drones since February, and its fleet is about four-fifths of its wartime size: about 135 against 165. Israel's drones and America's two carriers in the region are as they were. Putting these together, we estimate that America and Israel could hunt launchers today at about 0.85 of their 2026 rate (somewhere between 0.75 and the full 2026 rate), mostly because of the missing drones. In 2026 they knocked out about 8% of Iran's working launchers a day early in the war; 0.85 of that is about 7% a day. That is the line marked "today" in the charts below: shown as about 7% a day in the first, and as 0.85 times the 2026 rate in the second.

At today's estimated hunting rate, a two-month war would leave America's Patriot interceptors empty in about six simulations in ten, and its THAAD interceptors in about half. A few points either way change the picture: hunt half as well and both run dry in almost every case; hunt one and a half times as well and they rarely do.

How much faster?

So how much faster would the hunting have to be for a new war to do America no more harm than the last one? Note that the bar is measured against the 2026 rate, not against today's lower estimate. We ran a war as long as 2026's, 39 days, at different hunting rates and compared it with the real thing.

At the 2026 rate, the new war would cost less in dollars: about $8bn of interceptors against about $15bn in 2026, because Iran has fewer launchers than in February and America has fewer interceptors left to fire. But it would be worse where it matters. America would use about 70% of its remaining THAAD interceptors and about 80% of its Patriots, against about half in 2026, leaving very little for the next crisis. And because the Gulf states' own Patriots would run out first, more Iranian missiles would get through: American sites would take about 340 hits on buildings and equipment, against 228 in 2026.

To do no worse than 2026, America and Israel would need to knock out launchers about 1.25 times as fast as last time to hold the damage at 2026's level, and about 1.5 times as fast to hold interceptor use there. If Israel is right that Iran has rebuilt to 400 or more launchers, against our estimate of about 280, the bar rises to about twice the 2026 rate. Long-range strike missiles, Tomahawks and JASSMs, would cost about $6bn either way, as they did in 2026.

Slow to refill

The interceptors are the harder thing to replace. No new THAAD interceptors are due before April 2027; at planned production America's stock gets back to today's level around 2029, and to its pre-war level later still. Patriot and SM-3 stocks take until about 2029-31. Iran, if its damaged missile plants restart within a year as satellite analysts expect, could rebuild its long-range stock on a similar timetable.

The arithmetic does not say who would win a new war, or how long it would last. It says that counting Iran's missiles misses the point. The outcome depends on how many launchers Iran really has, which no one outside Iran knows, and on whether America and Israel can find them faster than they did twice before.