World

Israel’s Iron Dome, explained by an expert


A rocket launched from Gaza City, controlled by the Palestinian Hamas movement, is intercepted by Israel’s Iron Dome aerial defense system, on May 11, 2021. | Mahmud Hams/AFP via Getty Images

What it does, and how it has — and hasn’t — changed the conflict.

By now, you’ve probably seen the videos: dark skies, illuminated by exploding balls of light, like alien spaceships doing battle or a terrifying fireworks display, scored by air raid sirens.

This is the view of Israel’s Iron Dome, the aerial defense system the country uses to intercept incoming short-range rockets. The intensifying conflict this week between Israel and Hamas, the Palestinian militia in control of Gaza, has offered a renewed glimpse of the Iron Dome in action.

The system has been in place for about a decade, developed with heavy financial and technical backing from the United States. It is, according to Israeli officials, about 90 percent effective at blocking the short-range rockets commonly used by Hamas and other groups in the region.

The Iron Dome gives Israel what Jean-Loup Samaan, a research affiliate with the Middle East Institute at the National University of Singapore who has studied Israel’s missile defense, called an “insurance policy” — it reassures citizens and protects against loss of life and property damage.

But Israel’s ability to defend against these rocket attacks hasn’t altered how it responds to them, with airstrikes and artillery fire on Gaza or anywhere else rockets may be coming from. Palestinian civilians frequently bear the brunt of these strikes.

On the other side, faced with a defense like the Iron Dome, groups like Hamas try to overwhelm the system, launching dozens if not hundreds of rockets, knowing most will be intercepted and never hit their intended targets but hoping that if they send enough, at least a few will. As of Thursday, according to Israeli officials, militants in Gaza had fired 1,800 rockets in this latest round of fighting.

All of this raises questions about how the Iron Dome has — and hasn’t — changed the nature of the conflict. I spoke with Samaan to find out more about how both Israel and militant groups like Hamas see the defense system; why, despite having such robust protection from rockets, Israel still responds to them with overwhelming force; and whether having the system makes peace more or less likely.

Our conversation, which has been edited and condensed, is below.

Jen Kirby

What is the Iron Dome?

Jean-Loup Samaan

Iron Dome is an air defense system, meaning that its objective is to intercept incoming rockets on Israeli territory. The project started in 2007 and became active around 2011.

Basically, it has three components, which is the case for most air defense systems: radar that detects the incoming rocket; a command-and-control system that processes that information and then activates the third component, which is the interceptor — basically a missile whose role is to destroy the other rocket.

Jen Kirby

So the interceptor essentially blows up the rocket in midair?

Jean-Loup Samaan

Yes.

Jen Kirby

Is this system unique to Israel?

Jean-Loup Samaan

In a way; it’s unique because it’s the most advanced system for these types of threats. Meaning that — without getting into the details, and I’m a political scientist, I’m not an engineer — but you cannot defend against a rocket the same way you defend against a ballistic missile because of the trajectory, because of the range.

So Iron Dome, and its specific domain, which is destroying rockets, is quite unique. It’s unique because it was among the first systems to be designed and, so far, from what we know, the most effective one. You could argue that the Patriot System that the United States operates is a bit similar — but it does not cover low-range rockets.

Jen Kirby

So the Iron Dome was designed for this very specific threat of low-range rockets coming from Gaza or other places nearby?

Jean-Loup Samaan

Yes, and that’s the important part, because sometimes people think Iron Dome can detect and intercept anything, but it was designed for unsophisticated weapons like rockets. It cannot intercept ballistic missiles coming from Iran, for instance — that would be something that the other systems the Israelis are developing like David’s Sling or Arrow would have to intercept.

Even some of the weapons systems that Hezbollah [an Iran-backed Shia militia] in Lebanon is operating, like mid-range ballistic missiles, precision-guided weapons, these types of more sophisticated systems would be much more challenging to intercept.

Jen Kirby

So the Iron Dome is a very sophisticated system designed for relatively unsophisticated technology?

Jean-Loup Samaan

That’s the reason why if you check over the last decade, every time there’s an operation with Gaza, you have, first, the people who are fascinated with Iron Dome, and then you have the others in Israel who say, “This is a very expensive system designed to intercept very cheap rockets.” So, for sure, it’s impressive in terms of the technology it operates and the command of that technology, but it cannot, by itself, protect the country against all the surrounding threats.

Jen Kirby

Has the use of the Iron Dome influenced or changed how Israel thinks about defense?

Jean-Loup Samaan

Yes and no. There have been, obviously, some budgetary implications, because the money you invest on Iron Dome you cannot invest on other things. That’s also the reason why the Israelis have made that topic — Iron Dome and air defense more broadly — into a major component of Israel-US cooperation. It would be very difficult for the Israelis to sustain the costs involved with these systems on their own.

But if you look at Israeli operations over the last decade in Gaza, Iron Dome didn’t change the fact that the Israelis had to conduct airstrikes from time to time against Hamas, and conduct operations that also involved ground forces. I would be curious to see in coming days, because there have been talks about ground intervention, if that materializes, like it has in the past.

That actually tells you that Iron Dome is good to buy time, is good to protect the population — but it doesn’t really change the nature of the conflict. It doesn’t change the fact that the Israeli military still has to use airstrikes and possibly the threat of ground intervention [against Palestinian militant groups like Hamas].

Jen Kirby

Why do you think it that is — that it buys time but ultimately hasn’t diminished the escalation of the conflict, like we’re seeing now?

Jean-Loup Samaan

So that’s the reason why it is effective technically — but strategically, it doesn’t change the fact that the Israelis cannot rely on that completely. The most skeptical people on these systems such as Iron Dome are usually the armed forces. They consider that, yes, it’s good, but you cannot rely just on defensive means.

We’re talking about [groups like Hamas, which are] non-state actors. It’s not clear how rational they are, and if they can be compelled by the logic of the Iron Dome — the logic of deterrence that the Iron Dome implies. So that’s the reason why, after one decade of Iron Dome, it didn’t really change the situation, especially for the cities in the south of Israel.

I’m not saying that the Iron Dome is useless, I just think it’s like an insurance option. It’s a great way to reassure the citizens, also to avoid total disruption of daily life. But at the end of the day, this cannot be the only option.

Jen Kirby

So where does the Iron Dome fit into Israel’s broader military strategy?

Jean-Loup Samaan

Iron Dome is a significant component of the military strategy, as a defensive measure that either deters coming rockets or defends the civilian areas against one rocket that is coming.

But at the end of the day, the Israeli military culture didn’t really change. Traditionally, the Israeli military relied on an offensive posture. It’s not because they consider themselves an aggressive military power, but because they truly believe that it’s not possible, given the territory, to rely on defense. That would be the best way to lead to defeat, to failure, and to the destruction of the country. Since its foundation, Israel has always relied on this idea that you need to prevent an invasion or an attack on the country by offensive means.

So I would say it may balance a bit between offense and defense. But at the end of the day, Israel still relies on airstrikes and the ground operations, if it considers that it has to escalate to that level. And right now, we clearly see that the Iron Dome is used, but that it’s not the only component of the Israeli response.

Jen Kirby

But it seems to have also changed how Hamas and other militants respond. They’re firing dozens and dozens and dozens of rockets.

Jean-Loup Samaan

Yes. And that’s the reason why, while you have Iron Dome intercepting these rockets, you will also have the Israeli military trying to detect [and destroy] the launchers inside Gaza, because you cannot just wait and see how the Iron Dome intercepts these rockets. So they try as much as possible to target the launchers.

But this is very difficult. You can have mobile launchers. And this relates also to the discussion on what do you do if these launchers are in civilian-populated areas, hidden in schools, hidden in buildings in the middle of Gaza. It’s the same in Lebanon; it’s very difficult for Israel to detect the launchers.

Jen Kirby

Is there any signal that the Palestinian militias are trying to change or adjust their tactics in any way to get around the Iron Dome somehow?

Jean-Loup Samaan

There are several ways they have been trying to bypass the Iron Dome. The first is, as I said, to overwhelm the system. The more rockets you send, the more difficult it will be over the long term. I don’t think for a few days, that will be a problem.

Plus the risk of having two fronts — if you have salvos of rockets being sent at the same time from Gaza and South Lebanon. I don’t know the numbers, and probably some of them are classified, but I guess this could become an issue in terms of sustainability for the system. So overwhelming the Iron Dome is a tactic.

Another tactic is hiding the launchers, as I said. And the other thing we’ve seen is the use of tunnels. I think it was in 2014 when that was a big thing, these tunnels that Hamas had built [from Gaza into Israel]. Because the Iron Dome systems are designed to monitor missiles or rockets coming from Gaza. So if there’s something coming from inside Israeli territory, I assume it would be much more difficult for the radar to detect. So these are several ways the Palestinian militia groups have been trying to bypass the system.

Jen Kirby

Do you think the Iron Dome has fundamentally changed the nature of the conflict — how either Israel or groups like Hamas respond?

Jean-Loup Samaan

I would say simply that it’s not changing. It’s intensifying, clearly. But this has been an ongoing development for the last 10 to 15 years. And starting around 2006, with the conflict with Hezbollah, missiles and rockets became the major component of these groups. They’re much more effective than suicide bombing, because the Israelis have been much more effective at countering suicide bombing. So it’s not a new thing, but it’s clearly intensifying over the last [several] years.

Jen Kirby

Does Israel having these kinds of defenses diminish its need for dialogue or to engage in efforts to reach a ceasefire with Hamas?

Jean-Loup Samaan

I don’t know what’s the cause and what’s the consequence there, because you could argue Israel invested in and relies on these systems because they basically don’t trust that there’s any opportunity for ceasefire or any settlement of the conflict with Hamas — or, let’s say, Palestinian militias, because Hamas is not the only one in Gaza. If it was just Hamas, you could argue it might be possible to discuss and compel Hamas, but a lot of other militias have their own rockets.

So there wasn’t any window of opportunity anyway.

Jen Kirby

You mentioned that the United States had a big investment in the Iron Dome. Why is that — what’s the US’s stake in this?

Jean-Loup Samaan

Well, first, historically, the US started cooperating with Israel on air defense in the 1980s. So when missile defense became a significant component of defense investment in the US, Israel was very quickly involved. There’s a history of close ties between both countries in that field. So it would seem, in a sense, natural that a consequence of that is to support something like Iron Dome.

I think it was around the end of Obama’s first term, in 2012, that the US put a stronger emphasis on Iron Dome in terms of budgeting. I believe it was probably not just the politics behind it, but also the strategic assessment that the priority is to protect and to strengthen the defense of Israel vis-à-vis these types of rockets.

Jen Kirby

Has anything surprised you at all about what’s unfolding right now?

Jean-Loup Samaan

Apart from a few technical aspects, like the range of rockets coming from Gaza that seem to be improving. But I guess that shouldn’t be a surprise. That’s the nature of technology.

I don’t want to sound like a contrarian, but the only surprise I had was there was no surprise. This whole scenario looks so much like 2014-2015. This is the Middle East, coming back to the era before Covid. You have Palestinian groups launching rockets, the Iron Dome being used, and airstrikes at the same time. I doubt that this will lead to anything apart from destruction, and I don’t see any settlement of the conflict.