Iron Dome

March 28, 2016

The US and Israel have jointly spent billions of dollars developing Iron Dome, a defense system against surface-to-surface weapons—mortars, rockets, and missiles—targeting Israel. Launched by various terror groups from the land surrounding Israel and its occupied areas, indiscriminate attacks have played havoc with daily life in Israel for decades. The country needed a reliable defense for military, economic, and psychological reasons. Iron Dome answered the call.

Boasting an 85 to 90 percent success rate in some episodes, the system—which Israel continues to refine—has been called a “game changer.”

The United States has subsidized the cost of developing the system not simply to help an ally with a chronic need for such defenses, but in hopes that derivative systems may some day help defend US forces from missile attacks as well.

Iron Dome reassures Israeli citizens, who now have less to fear from rocket attacks. As it improves, it reduces the tactical and propaganda value of such attacks to Israel’s enemies.

However, Iron Dome’s success against cheap forms of attack may drive Israel’s adversaries to seek ever more powerful weapons.

Iron Dome works by sensing an incoming weapon with radar, deciding where the weapon is headed, and targeting the genuinely threatening rounds with a high-speed missile. The system works in all weather, is mobile, and can also approximate the location of the enemy’s firing position, according to its creator.

Its main limitation is that it can be overwhelmed by large salvos. The system is least effective against guided missiles and the smallest rounds, such as mortars and short-range rockets.

“The Iron Dome by itself doesn’t give you full protection from all missile attack,” said Ilan Goldenberg, director of the Middle East Security Program at the Center for a New American Security. However, it was never meant to be a leakproof defense.

Iron Dome is the umbrella name for two subsystems, the dual-mission counter rocket, artillery, and mortar (C-RAM) and very short-range air defense (V-SHORAD) system. It was developed by Rafael Advanced Defense Systems and went operational in 2011.

The system got its first taste of combat in 2012, during what was later named Operation Pillar of Defense. Hamas in Gaza attempted to fire more than 1,500 rockets at Israel, 400 of them deemed threats. Of those, the Israeli government says 85 percent were intercepted by Iron Dome. Four civilians were killed by the attacking rocket fire during the conflict.

Iron Dome works in the following sequence: First, it recognizes incoming short-range fire (up to roughly 45 miles away) using its multimission radar.

Next, using its mobile battle management and control unit, it determines whether the round is headed toward a populated area—say, an outdoor restaurant or a gathering of soldiers.


If the system determines that an intercept is necessary, it fires one of its Tamir missiles (there are 20 per battery) from a mobile unit.

Critically, it can discriminate between rounds that don’t pose a real danger from those that do—and concentrate its fire accordingly.

The principal drawback of Iron Dome is its cost. The Katyusha rockets favored by Hamas and Hezbollah typically cost about $300 a round, while the Iron Dome’s Tamir missiles cost anywhere from $20,000 to $100,000 each, depending on whose numbers are being quoted. (The Israeli government will not officially disclose this information.) Also, some sources suggest that two Tamirs are fired at each incoming projectile to ensure success, which, if true, would double the cost of each interception.

On the other hand, the cost of a successful rocket attack—in terms of lives, physical destruction, and propaganda value for the attacker—can be enormous, and in Israel’s view, make the cost of Iron Dome well worth it.

Another shortcoming is the relatively small magazine of missiles each unit can fire. In a volley of hundreds of missiles at once—a rarity—the system could be overwhelmed by sheer numbers.

Guided missiles, which can alter their course en route to the target, are also a challenge for Iron Dome, but neither Hamas nor Hezbollah have yet utilized such weapons.

Yiftah S. Shapir of the Institute for National Security Studies—a nonpartisan Israeli think tank—wrote in a 2014 INSS paper that Iron Dome is the right system to deal with very short-range rocket fire.

Israel has been plagued by “prolonged rocket fire since 1968,” Shapir wrote in “The Lessons of Operation Protective Edge,” a paper about the 2014 campaign against Hamas in Gaza. Hamas, he said, had been relying on rocket fire to attack Israel since 2001, and the 50-day Protective Edge was the second—and successful—trial for Iron Dome.

At the beginning of the conflict, Hamas’s inventory comprised Chinese- and Iranian-made 107 mm rockets; 122 mm Grad rockets for short range; upgraded Grad rockets for long range; Iranian-made Fajr-5 rockets; Syrian-made 302 mm rockets; and Hamas-made Sejil-55, M-75, and J-80 rockets.

Hamas had been launching rockets against Israeli civilian and military targets with increasing frequency into the summer of 2014, reaching a peak of about 150 a day against Tel Aviv, Jerusalem, and the Carmel coast. Throughout the operation—officially lasting from July 8 to Aug. 26, 2014—Hamas (and other organizations) launched more than 4,500 rockets.

Here is where Iron Dome’s ability to discriminate between dangers and wayward attacks proved its mettle: Eighty percent of those incoming rounds—about 3,600—headed toward locations that didn’t pose a threat to Israel. Another 200 failed en route. Iron Dome intercepted 735 of the dangerous launches and missed 70, according to the INSS report.

Although that’s a 90 percent success rate, what constitutes success

“Because the stuff that’s being shot down with this is not very technologically sophisticated,” noted Goldenberg of CNAS, “it’s hard to overwhelm the system.” Iron Dome’s success is due in part to the reality of asymmetric warfare with low-end materiel in enemy hands, he suggested.

Realistically, though, Iron Dome’s place is how Rafael describes it: the “lower layer” of Israel’s multilayered air and missile defense network.

Seven civilians died during Protective Edge, two by rocket fire. In comparison, during the Second Lebanon War in 2006, 53 civilians died by rocket fire. Hezbollah fired about 4,000 rockets into Israel as opposed to Hamas’ 2014 figure of 4,500.

Though saving lives is the top priority, Iron Dome does much more than keep Israelis alive: It helps them feel reassured about their security.

Confidence and Calm

“You hear those air raid sirens go off, which means there’s a rocket in the air,” a former senior US government official told Air Force Magazine, having experienced the system firsthand in Tel Aviv during 2014’s conflict.

“And if you can hear those sirens, then probably the rocket’s coming your way. And to hear the Iron Dome battery go off, and then to hear the explosions in the air gives a civilian population a huge sense of comfort,” he said. “That goes a very long way in keeping people calm. It goes a very long way in creating a sense of confidence in the defensive capabilities of Israel.”

That calm allows Israeli leaders to “think through options or to nuance options,” he said.

“Public mood can translate into concrete strategic benefits,” wrote Emily B. Landau and Azriel Bermant in the INSS Protective Edge paper. The success of Iron Dome during the 2014 operation reduced the “pressure” to retaliate with a ground attack into Gaza, they observed.

It’s anyone’s guess, however, how much of Iron Dome’s success is real. Michael O’Hanlon, co-director of the Center for 21st Century Security and Intelligence with the Brookings Institution, said he’s “skeptical” about those 85 and 90 percent success rates touted by the Israeli government.

“I’m dubious anytime you start quoting double-digit success rates for a defense system,” he told Air Force Magazine.

Even if accurate, those numbers need to be viewed in context, O’Hanlon said. Iron Dome defends against a very specific, low-end threat. He believes it’s not “healthy” to sell the Iron Dome as some kind of “incredible savior.”

Whether Iron Dome is all it’s cracked up to be or not, the US clearly supports it, if American funding is any indicator.

“Israel is one of our most precious allies on the planet,” the former senior official said. “Our intent is to do what we can to support Israel in its defense.” Congress has been “very forthcoming in helping with the development and procurement of the system,” he said.

Goldenberg said it’s common for the Israeli Defense Forces to show off the missile batteries to US lawmakers who help fund them; he’s visited one himself on just such a congressional fact-finding tour in Israel.

As of June 2015, the US has given Israel a little over $1 billion specifically for Iron Dome batteries, interceptors, co-production costs, and general maintenance, according to a Congressional Research Service white paper about foreign aid to Israel.

Israel is the “largest cumulative recipient of US foreign assistance since World War II,” having received $124.3 billion over some 70 years.

Because Israel developed Iron Dome on its own, it kept technical details of the system proprietary for several years before beginning to share them with the US in March 2014. In September of that year, Rafael awarded US-based Raytheon a contract worth $149 million to provide parts for the Tamir interceptor.

The enacted Fiscal 2016 National Defense Authorization Act provides $41.4 million for Iron Dome.

Like the US military’s Future Years Defense Program, a five-year roadmap of spending, Israel has its own five-year plan. The newest one, nicknamed the “Gideon” plan, will fund the Ministry of Defense with about $15 billion annually. It includes money for increased defenses against groups like Hamas and Hezbollah.

“The significant aid extended by the United States is extremely useful, but it cannot serve as a substitute for Israel’s allocating the resources needed,” wrote Assaf Orion and Udi Dekel in January’s “Strategic Survey for Israel, 2015-2016,” an annual publication from the INSS. They argue that the Iron Dome’s “key challenge” is adding enough batteries to provide “concurrent protection to civilians, IDF facilities, and critical infrastructure.”

The official who heard the system intercept incoming rounds in 2014 agrees.

“I remember thinking to myself—and I’ve been under fire a lot— … ‘Isn’t this terrific?’?”