April 21, 2024

Thoughts on the Iranian Missile Attack

Last weekend saw one of the largest missile attacks in history, almost totally blocked by the defenses of Israel and various countries that came to Israel's aid. As such, it's worth a look to see what lessons we can learn. For those who weren't paying attention, reports generally seem to agree that Iran (and its proxies in Yemen) launched about 170 drones, 30 cruise missiles and 110-120 ballistic missiles. And to be clear, 300+ missiles (some sources are saying 350, probably with the balance made up by more drones) is a lot. For comparison, during the first Gulf War, the United States launched 288 Tomahawks. Obviously, that was in the context of a much larger air campaign, but this was clearly more than just lobbing a few missiles as harassment.

But the attack was a complete failure, with the net result reported of two Israeli airbases damaged (not clear exactly how much) and a single girl left in critical condition by falling debris. Some of this was because about half of the Iranian ballistic missiles failed during launch and crashed short of the target1 but most of it was a superb performance by Israeli and American ABM systems, and the rapid work of an impromptu coalition of basically everyone who wasn't Iran in the region to deal with the atmospheric threat.

Focusing first on the ballistic missile aspects, I want to say that I was right about the capability of modern ABM systems, and if anything underestimated how well they would handle a large-scale attack. Most of the missiles seem to have been handled by the Israeli Arrow 3 and David's Sling systems,2 but USS Arleigh Burke and USS Carney, operating in the Mediterranean, are credited with getting a few of them, too, and they provide us with our best window into the performance of ABM systems. Four to seven SM-3s were launched, downing four to six ballistic missiles. CENTCOM is claiming the total is six, which in turn would imply that it's likely 7 SM-3s were launched, for an 85% hit rate in its first combat test, although even the 57% resulting from worst-case numbers is still quite good. Critics of ABM also frequently claim that while the system may work when faced with one or two test missiles, it will be overwhelmed by an actual attack, and it's worth pointing out that whatever the threshold is, it's clearly somewhere north of 50.3 As it was, we have reports that 4 missiles got through near one Israeli airbase, and none hit anything critical. It's unclear if this was luck or an extension of the long-standing practice with Iron Dome of ignoring inbound weapons that will land in unpopulated areas.

As for the atmospheric efforts, the interesting thing here was the formation of an impromptu coalition to defeat the attack, containing not only Israel's traditional allies like the US and UK, but also traditional enemies among the Arab states. Early warning reportedly came from Saudi Arabia and the UAE, who Iran gave advance notice about the attack to, and who passed said notice onto the US, giving it time to prepare for the attack. Later, it was their radars which picked up the launch of the Iranian drones, information that allowed the US-led plan to swing into action. The Iranians apparently attempted a coordinated attack, with all of the weapons arriving at the same time, but this meant the slow drones gave everyone several hours of notice, including those watching at home.

The vast majority of the drones and cruise missiles4 were shot down by the combined efforts of the Israeli Air Force, the USAF, the RAF and the Royal Jordanian Air Force. The USAF contingent, Strike Eagles flying from an unknown base in the Middle East, is credited by CENTCOM with 80 drones5 while the Jordanians reportedly shot down 20% or so of the attack in defense of their own airspace. The RAF contributed an unknown number of Typhoons flying from RAF Akrotiri in Cyprus, but the lion's share had to be done by the IAF's own fighters, a mix of Eagles, F-16s and F-35s. France also participated in an unclear capacity, most likely shooting down Yemen-launched drones and/or missiles with ships in the Red Sea.

The ineffectiveness of the attack has led a number of people from Joe Biden on down to suggest that Israel shouldn't retaliate, a position I find rather silly given the scale of the attack. And it appears that Israel isn't going to take that approach, having launched an attack of some sort on targets near the Iranian city of Isfahan. The Iranians are claiming it was a drone attack that was successfully countered, but it looks more likely that the drones were for post-attack surveillance and the actual attack was carried out by air-launched ballistic missiles, with unclear results. All sources seem to agree that it wasn't targeted at the Iranian nuclear facilities around Isfahan, and it appears to have attacked one of Iran's four S-300 SAM batteries. This pretty much confirms the theory that this strike was intended to reassure the Israeli people that they have done something and remind the Iranians that their defenses won't handle an Israeli attack nearly as well without pushing them into continuing escalation. In all honestly, they probably handled it better than I would, as my first reaction was that we should take away Iran's navy. To be fair, I'm still not sure that would be a bad policy for the US, given Iran's continuing provocations.

1 A significant part of why US weapons are so expensive is because we make very sure this kind of thing doesn't happen.

2 It's worth noting that the US and Israel have been working together on missile defense for decades, and both systems are coproduced by American companies, so their performance speaks to the capability of US BMD as well.

3 A US Army Patriot battery near Erbil, in northern Iraq, is also credited with one of the ballistic missiles, but I strongly suspect this was one of the ballistic missiles that failed on launch. Erbil is close to the Iranian border, and it's unlikely Patriot, which is a fairly short-ranged missile, would have the energy to chase down a ballistic missile bound for Israel.

4 I have argued against this distinction before, but some recent work in Command has convinced me that while there may be no philosophical distinction between the two types, there is in fact a significant practical distinction between a weapon that travels at ~100 kts and one that does 400+ kts, and it makes sense to talk about them separately.

5 This is almost twice as many air-to-air kills as the US has managed since the end of Vietnam, although one could make the argument that drones don't count, as I'm sure the USN is doing right now.


  1. April 21, 2024EngineOfCreation said...

    "Taking away Iran's navy" seems like a big step up on the escalation ladder. If you want to look tough at home but don't want an actual full on war, you retaliate with less intensity, not more.

  2. April 21, 2024bean said...

    I never said that taking away Iran's navy would be deescalatory. Except in an "escalate to deescalate" sort of way.

  3. April 21, 2024EngineOfCreation said...

    I didn't say you said that. I'm saying it would be a bad idea.

  4. April 21, 2024ack-acking said...

    Any guess on how many ABMs Israel and its allies have in the region? My worry is that, while its certainly impressive how many missiles they shot down, they would get overwhelmed by Iran simply firing more missiles. Reports say they have over 3000 ballistic missiles stockpiled, plus who knows how many small rockets in hezbollah, so they could ramp up this strike quite a bit. I'm not sure how much extra capacity Israel has for defense.

  5. April 23, 2024megasilverfist said...

    " given Iran’s continuing provocations" given that the missile attack was in direct retaliation for an Israeli strike does it actually make sense to assume the Iran will continue provocating if it isn't itself provoked?

  6. April 23, 2024Basil Marte said...

    megasilverfist: it is treated as known that Iran supplies the interesting anti-shipping capability to the Houthi, the ones who shot random commercial ships passing on the Red Sea to/from Suez and the Med, see earlier post Excitement in the Bab el Mandeb. They also recently captured the MSC's Aries, a container ship, elsewhere (around Hormuz).

  7. April 23, 2024Anonymous said...

    If the Israelis came out and said that Iran was using diplomatic buildings for arms smuggling not many people would disbelieve them.

  8. April 24, 2024CmdrKien said...

    The Strike Eagles probably came from the same base that had F-22s and F-35s stationed at last year. It’s possible for them to have come from elsewhere in the region, but the strange non-specificity of where they are is familiar compared to the press releases on those deployments, and the location of this base would make it easy to transit to do the take downs.

  9. April 28, 2024Ski206 said...

    The performance of the F-15Es with their new AESA radars is certainly very impressive as these are not as easy a target as one might think at first glance. Given the need to be able to stop strikes of this kind there is a very strong argument that the USAF should be buying a lot more EX not less. Especially when you think about the range of this platform in a Pacific fight, its ability to carry a large number of weapons, and its ability to launch those weapons with a lot of kinetic energy.

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