Few secrets are more closely guarded than the state of a country’s missile defences. Knowing how well attacks are working—by observing the effort required to stop them—is valuable intelligence. So it was striking when, on March 10th, Ukraine’s defence ministry said that in the first three days of the war with Iran, Gulf countries had fired 800 American-made Patriot interceptor missiles at incoming Iranian missiles and drones. That is more, it noted, than the 600 Ukraine had fired in four years of war against Russia.
Gulf states are burning (AFP)
The Ukrainians later admitted their numbers referred only to certain advanced Patriots, not all types; they also seem to have been estimates, rather than classified information provided by allies. But the claims raised important questions—and rough calculations are possible. How fast are Gulf countries and America running through their Patriot stocks? And how does their use compare with Ukraine’s?
In response to attack by ballistic missiles, Gulf commanders tend to fire at least two interceptors to maximise their chance of success (Ukrainians have to be more frugal). Drones present a different problem: many are shot down by aircraft or cheaper weapons. But not all. Fabian Hoffmann of the University of Oslo suggests that 5-10% of them are blocked by missile-defence systems.
Such figures make it possible to estimate interceptor use. Reports from Gulf countries suggest they have taken out, with the assistance of American batteries, at least 887 Iranian missiles and 2,581 drones. Assuming an average of two interceptors per missile and one for every 20 drones, some 1,900 interceptors have been used. If commanders are being extra careful, using three interceptors per incoming missile, and if a higher share of drones are shot down, say one in ten, then the tally is almost 3,000. Even this may be an undercount. Our calculations take into account only successful, reported attempts at foiling attacks.
If our analysis is correct, some countries’ stocks may be running low. Although the exact number of Patriots each has bought is secret, the American government must authorise sales. And such authorisations, which set an upper limit on purchases, are public. According to work by Mr Hoffmann, Saudi Arabia may have bought 1,800 Patriots, Qatar 1,000 and the United Arab Emirates 900. America also has stocks in the region, though their size is unknown.
Missile-defence systems are expensive. THAAD and NASAMS interceptors are also used, yet roughly 90% of the missiles are likely to be Patriots, which cost $3m-6m each, depending on the variant and who bought it. Our estimates therefore suggest a combined outgoing on interceptors of at least $5.1bn. Some armed forces may in time reveal their spending. “I expect the figures will be shocking,” says Tom Karako of the Centre for Strategic and International Studies, a think-tank.
No country has more recent experience of incoming drones and missiles than Ukraine. On March 5th Volodymyr Zelensky, its president, said that America had asked him to send experts to the Middle East. Ukraine’s defence industry has, among other innovations, developed “first-person view” interceptor drones, which cost the country’s armed forces $2,500 apiece (but would be more expensive for other countries). These have become adept at bringing down drones like the Iranian-designed Shahed-136, as well as modernised Russian versions. Several Gulf states have already expressed interest, officials say. Yet Ukraine still struggles to defend itself against ballistic missiles. PAC-3 Patriots represent its best option, and the country has limited stocks.
That shortage explains why so many more Patriots seem to have been used in the Gulf. Our analysis finds that the Ukrainian defence ministry’s estimate, of 800 by the third day, is plausible. Even including PAC-2 Patriots—a cheaper, more limited interceptor, which The Economist understands Ukraine has launched slightly more of—usage in the first three days of the Iran war is comparable to that for the whole four years in Ukraine. Mr Zelensky would love to have more advanced interceptors available: he knows that the cost of a Patriot is nothing compared with the cost of a missile that makes it through.
