May 8, 2013
By Uzi Rubin – Iron Dome, Israel’s short range missile defense system, is the country’s somewhat belated response to the recurring barrages of rockets fired at its population centers. Conceived in 2005, Iron Dome went into full-scale development in 2007 and was first put to use in 2011. Although the system was used in combat before being declared fully operational its performance on the battlefield was impressive. In recurring cycles of violence along Israel’s border with Gaza, it provided solid protection to Israel’s southern cities, substantially reducing casualties and physical damage, thereby boosting the sense of security and resilience on Israel’s home front. Iron Dome’s most celebrated combat engagement to date occurred during the week-long fighting between Israel and Hamas in Gaza in November 2012, when five Iron Dome batteries defended most of Israel’s southern cities, as well as Tel Aviv, against a barrage of more than 1,500 rockets.
Recently, however, a number of skeptics have voiced doubts over Israel’s proclaimed success rate of Iron Dome during the recent fighting. Originally, the criticism came from the United States, but some of that sentiment has been echoed within Israel. Beyond the immediate security of Israel’s population, the issue of Iron Dome’s actual performance has significant implications for the debate on the technical viability of missile defense – a subject of contention for decades. . If Iron Dome does in fact work as advertised over the skies of southern Israel, this could strengthen arguments in support of missile defense systems in the U.S. Iron Dome’s success could also have a much broader impact on debates regarding European and strategic missile defense, a Gulf missile defense system, and policy options towards a potentially nuclear Iran. In all of these cases, debates about the technical viability of missile defense systems play a major role.
This article contextualizes the debate on Iron Dome’s performance and proceeds to discuss its details, using open source information to refute the claims of Iron Dome skeptics.
Iron Dome in Action
Israel deployed a theater missile defense system (dubbed “Arrow”) more than a decade ago. Yet the decision to develop smaller scale defenses against the threat of short range missiles from Lebanon and Gaza was accompanied by much soul searching. Only the shock of the 2006 Lebanon War, when 4,000 Hezbollah rockets killed 53 Israelis and hundreds of thousands evacuated their homes, compelled Israel’s minister of defense to overrule internal opposition and order a crash program that was dubbed (somewhat flamboyantly) “Iron Dome.” Kick-started by Israel’s Ministry of Defense, it was tested extensively in Israel’s southern test range during the summer of 2010.
Iron Dome achieved its first combat success in the evening hours of April 7, 2011, when it intercepted and destroyed a Palestinian rocket targeting the city of Ashkelon.
Since then, a steadily increasing number of Iron Dome batteries have been deployed to defend more Israeli cities. Iron Dome batteries participated in recurring cycles of fighting in October 2011, March 2012, and June 2012 (to mention a few), during which hundreds of Grad rockets were fired at Israel’s southern cities. In total, Iron Dome intercepted more 100 rockets during those episodes. Some failures and malfunctions were registered but generally the system worked well, its teething problems were gradually resolved, and its success rate kept growing.
The ultimate test to date of Iron Dome came during Operation Pillar of Defense, when about one-third of the 1,500 plus rockets fired from Gaza were destined to hit within Israeli population centers. Compared to previous rocket campaigns when no defense was available, Israeli casualties and physical damage were sharply curtailed.
According to the Israel Air Force (IAF) spokesperson, of approximately1,500 rockets fired from Gaza during the conflict, 480 or so rockets were about to fall within residential areas,421 of which were destroyed by Iron Dome in the air (more than 84% success). Only 54 rocket hits were registered in built-up areas. The rest either targeted nonresidential areas or flew harmlessly into the sea.
The general impression within Israel (and among outside observers) was that the number of casualties and level of physical damage from the intense barrage of rockets was significantly more limited, compared to previous experiences from similar campaigns. Iron Dome was a game changer that saved lives and property while providing the Israeli Government with a leeway to avoid escalation and negotiate a cease fire on relatively favorable terms.
The Skeptic’s Case
Nevertheless, a number of observers have questioned the official figures on the success rate of Iron Dome. For instance, Dr. Theodore Postol, of the Massachusetts Institute of Technology (MIT), wrote a technical paper titled “Indicators of Iron Dome Performance in Pillar of Defense” (unpublished), the main conclusions of which were first made public by political scientist and journalist Dr. Reuven Pedahzur, an Israeli critic of missile defense. Postol reiterated his case in an op-ed in Israel’s Haaretz daily. Almost concurrently, another American critic, Mr. Richard M. Lloyd, expressed his doubts to a New York Times reporter.
The skeptics base their arguments on their own notions on how Iron Dome ought to work as well as on video clips from spectators’ smartphones and media footage. They argue that the true success rate of Iron Dome was much smaller than claimed by Tel Aviv because what they saw in the video clips did not fit with their notions on how a successful interception should look. In their analysis, successful interceptions in which the incoming missile’s warhead is destroyed should produce two balls of fire or two clouds of smoke – one by the exploding Iron Dome warhead and one by the hit missile.
Second, critics cite the number of claims for damage compensation in support of their argument. Namely, the record shows that following Operation Pillar of Defense, Israelis filed 3,165 damage claims, and skeptics insist that if indeed only 58 rockets exploded inside built-up areas, the number of claims would have been much smaller. Consequently, they reason that indicates that Iron Dome missed a much higher number of rockets.
Dr. Postol accuses the Israel Defense Force of hiding the true number of rocket intercepts over built up areas and the Government of Israel -of lying about it to the United States to secure additional funding from the U.S. and sell the system to others. While Postol and Lloyd argue that the actual number of missiles that Iron Dome successfully intercepted was much lower than Israel’s official claims, their conclusions diverge: Postol believes the success rate to be 10% at best, and Lloyd estimates it at 40%.
Misunderstanding How Iron Dome Works
In 1991, Dr. Postol correctly refuted U.S. Army claims about the success of the Patriot air and missile defense system during the Gulf War. Using publicly available video footage, he showed that instead of the proclaimed success rate of around 80% the real rate was close to zero. Subsequently, the U.S. Army retracted its claims and conceded that Postol’s arguments were essentially correct. At the time, the Patriot’s poor performance had already been an open secret, even before Dr.Postol’s study came out. As I can testify from my own experience in Tel Aviv during that war, the lack of success of Patriot became glaringly apparent to the public shortly after it went into action. Simply put, it was obvious that the Scud warheads were exploding on the ground rather being destroyed in the air. Thus, although Dr. Postol was the first to publicize the failure, he was not the first to notice it.
The reason for the erroneous evaluation of Patriot’s performance by the U.S. Army is also well known by now. It had to do with a faulty scoring logic programmed into the system – a typical beginner’s mistake in a new type of warfare, a mistake which has been corrected and learned from. In fact, it was the 1991 failure of the Patriot system, along with increasing threats from short- and long-range missiles that pushed Israel to develop its own missile defense system and endowed Dr. Postol with an aura of infallibility in some circles.
In order to better understand the drawbacks in the critics’ line of reasoning, it should be noted that Iron Dome interceptor is equipped with a warhead that is designed to cause a detonation of the hostile rocket’s warhead. Lloyd expects that a successful kill of a hostile rocket should be signaled by two distinct explosions: first, the warhead of a missile fired from the Iron Dome battery, then the target’s warhead. Examining hundreds of online videos of Iron Dome in action, Mr. Lloyd found only few that showed two smoke clouds (in daytime) or two fireballs (at night).
Nevertheless, as seen in videos from the 2010 tests, the two explosions are practically indistinguishable – they happen too fast for the human eye or a commercial video camera to capture. This is supported by the few action videos which can be attributed to specific times and places. For example, all existing footage from a nighttime attack by a single heavy rocket on Tel Aviv on the night of November 18 show the target being destroyed in one huge flash, too powerful to have emanated from just the impact of the Iron Dome’s warhead. Only one single fireball – yet no hostile rocket hit Tel Aviv that night.
Dr. Postol makes a more elaborate case. First, he reconstructs a quantitative model of Iron Dome’s kinematics during the interception process and the working of its warhead. From this he derives his prediction on how a trajectory of a successful intercept should look like on video. Since most of the trajectories of missiles fired from Iron Dome batteries, seen on YouTube clips, do not correspond with those trajectories, Dr. Postol assumes that they failed. He therefore conjectures (a “guess based on incomplete data” as he writes in the report) that no more than 5% to 10% of the incoming rockets were actually destroyed by Iron Dome.
For obvious reasons, Israel has never revealed any details of Iron Dome’s specifications, including kinematics during the interception process. Dr. Postol’s reconstruction is thus based on his own notions of what those specifications should be – which are erroneous. Consequently, his understanding and calculation on how successful intercepts should look like are also largely wrong, as are his general conclusions.
Another source of Postol’s error was his methodology of data mining from public imagery. Unlike the videos from the 1991 Gulf War where the glowing trails left by the red hot Scud warheads could be clearly seen, the much slower (hence cooler) rockets of 2012 did not leave any trails and were not visible in publicly available photographic material. With no idea where the targets were, any attempt to determine their relative positions vis-à-vis the interceptors was no more than a wild guess. The critics deductions were thus as valid and accurate as “trying to perform an operation on a patient with closed eyes”. The skeptics’ case thus does not stand up to scrutiny. Moreover, independently verifiable data poses a glaring contradiction to these statements, as discussed below.
Independently Verifiable Measures of Effectiveness (MOE)
Damages and casualties are two independently verifiable measures of effectiveness (MOE) of any defense or weapons system. The best benchmark for Iron Dome’s MOE is the 2006 Lebanon war: it took place before Iron Dome was operational, but similar types of rockets were used against similarly sheltered population that was given effective early alerts. If the skeptics were right, then, relatively speaking, the levels of casualties and damages should have been relatively similar in 2006 and 2012. Yet, examination of the verifiable damage and casualty data from both events indicates a sharp relative drop that cannot be explained by factors other than a high scoring Iron Dome.
Damages. Here it is helpful to briefly describe Israel’s policy regarding damage compensation. By law, Israel’s Treasury compensates civilians for any damage from enemy action. There is no minimum threshold: even a single broken window or scratched car paintwork is eligible for compensation. Israelis take advantage of this policy with gusto. The total number of damage claims posted by citizens is on record on Israel’s Treasury website. The 4,000 rockets fired in 2006 resulted in no less than 30,000 damage claims. Comparing it to the 1,500 rockets of 2012 and adjusting for the higher concentration of fire, about 14,400 claims could have been expected had Iron Dome not existed. Yet, only 3,165 claims were actually filed. Iron Dome’s high score is the only plausible explanation of this relative drop of about four fifth (i.e. about 80%) in the number of claims. Although Postol cites the number of claims filed as evidence that the system’s success rate was much lower, a comparison between claims filed in 2006 and 2012 shows the opposite.
Casualties. Somberly, fatality statistics provide incontestable evidence of the rockets’ lethality. Funerals are public and the name of each victim (often with his or her portrait) is widely reported. Postol cites the 6 fatalities of Pillar of Defense as another proof of his claim. Yet, these statistics prove the opposite.
In the 2006 war, 53 Israelis were killed as a result of 4,000 Hezbollah-launched rockets. Extrapolating for the more concentrated fire of the 1,500 Hamas’ rockets in 2012, about 26 Israelis should have died from rockets had Iron Dome not existed. The actual number of rocket fatalities stood at five (a sixth person was killed by a mortar bomb). Once more, the drastically lower number of victims (about 80% lower than expected) could only be attributed to Iron Dome’s high interception rate and tallied well with the relative reduction in damage claims. There are about 20 or so Israelis today who owe their lives (and many more who owe their health) to Iron Dome.
Finally, and in contrast to the events of 1991 and 2006, this time no noticeable relocation of residents away from the stricken communities in southern Israel was registered. They cast a vote of confidence in Iron Dome by staying at home and sticking it out.
Israel’s Response to the Critics
Israel’s officially reported success rate for Iron Dome is not based on data mining from public domain photography, but on complete, three-dimensional and minutely detailed sky pictures obtained from its array of sensors tracking and recording every moving object above southern Israel, targets and interceptors alike. Every engagement, whether successful or not, was played, replayed and cross-correlated with detailed ground mapping of impacts and debris. This meticulous process is vital not only for verifying interceptions but even more so for fault analysis and correction. Publishing any of the raw sensor data could be used by hostile factions in the future to devise more lethal tactics, endangering Israeli lives. Hence this data is currently confidential and will probably remain so as long as the rocket threat persists.
When Dr. Postol’s allegations became known through Reuven Pedahzur’s Haaretz article of March 8, 2013, the Israel Ministry of Defense issued a strong rejection on March 13, 2013, referring to Postol’s claims as “baseless,” and reaffirming that Iron Dome’s success rate in Pillar of Defense stood at more than 80%.
Unlike the case of measuring the Patriot’s success rate in 1991, where the “facts on the ground” proved U.S. claims observably wrong, and the U.S. army had to retract these claims, the skeptics’ attack on Iron Dome did not cause any retraction or even modification of Israel’s claims. In an April 15, 2013 interview, the Director of the R&D Directorate in the Israel Ministry of Defense, General Ophir Shoham reiterated that Iron Dome’s success rate stood at over 84% and rejected Postol’s allegations that Israel had misled the U.S. In his words, “The entire (Iron Dome) program is under close U.S. scrutiny. When the U.S. offers financial support, as it does in the case of Iron Dome, it makes sure the money is spent for a good purpose.” Israel’s aggressive media usually makes a short thrift of any attempt of government cover-ups. If it had any substance, any vast conspiracy to falsify Iron Dome’s true score, as alleged by the critics, would have been exposed by now. That this has not been the case is an indication that such a cover-up does not exist.
The recent episode, challenging the accuracy of claims about Iron Dome’s success rate in Operation Pillar of Defense, is the latest manifestation in a persistent campaign against missile defense at large. This campaign, dating back to the Cold War, is rooted in the fundamental issues pertinent to nuclear stability and strategic defense. To make their case more palatable to the public, some critics have transferred the debate to the technological domain. The Cold War has ended but the technological objections are still with us. The notion that missile defense might really work – even on the small scale of Iron Dome – is too irksome for missile defense opponents.
As I have demonstrated, all evidence points to the effectiveness of Iron Dome, and Israelis, as well as the U.S. Government, are confident that it works. Moreover, the Israeli public, known for its cynicism and skepticism, supports Iron Dome overwhelmingly. At a time when growing instability in the Middle East is threatening to exponentially increase the missile and rocket threats from armed non-state groups, missile defense is becoming even more essential in Israel’s national security doctrine. The ongoing support of President Obama to Israel’s missile defense programs is an essential component in the efforts to maintain regional stability.
Uzi Rubin was the first Director of Israel Missile Defense Organization. Between 1991 and 1999, he oversaw the development of Israel’s Arrow anti-missile defense system. He was awarded the Israel Defense Prize in 1996 and 2003.