More than a Missile: Judging Iron Dome


There are many important strategic, political, legal, and moral questions to ask about the latest round of fighting between Israel and Hamas in Gaza. One important set of questions revolves around the efficacy of Israel’s “Iron Dome” rocket interception system. While there has been some dispute about the tactical effectiveness of the system, Iron Dome has had important strategic and political effects in allowing Israel to pursue a set of military objectives that is narrowly focused on locating and destroying Hamas’s network of tunnels. Without the success of Iron Dome in striking down rockets headed towards Israel’s population centers, Israel likely would have felt forced to pursue a much more extensive military operation, similar to operations conducted in the West Bank and Gaza, and in Lebanon, since the outbreak of the Second Intifada in 2000.

Tactically, Iron Dome’s effectiveness can be measured by the extent to which the system does what its designers intended it to do. Iron Dome is part of Israel’s multi-layered missile defense system. This system includes Arrow, designed to intercept ballistic missiles, David’s Sling (which is not yet operational), designed to intercept large caliber artillery and short-range ballistic missiles, and Iron Dome, which is intended to intercept shorter-range rockets like those fired by Hamas and Hezbollah when they are aimed at populated areas. The system works by detecting the trajectory of an incoming rocket right after it is launched, and only dispatching an interceptor if a projectile fired by an adversary is heading for a populated area. While some reports have questioned the effectiveness of Iron Dome, most suggest that the system achieved significant successes in knocking down almost all of the missiles that were headed towards Israeli cities—several hundred out of the more than 3,000 fired at Israel in the past month. Anecdotally, we know that there have been almost no successful strikes on Israeli population centers and that two of the three Israeli civilian casualties during Operation Protective Edge came from short range mortar strikes, against which Iron Dome is not effective.

Most of the data that would support definitive evaluations of the tactical effectiveness of Iron Dome are in the hands of the Israeli military, so conclusive evaluations will have to wait until after the war (and are no doubt already taking place within the corridors of the I.D.F.). But from what can be observed at this stage, the system seems to have chalked up significant tactical achievements.

Strategically the picture gets more complicated, and whether Iron Dome can be considered a strategic success depends in part on how one defines it. But here too, the system appears to have made an important contribution to a shift in Israel’s objectives, making them more narrow and achievable. Specifically, over time, the objectives of Operation Protective Edge changed from the broader aspirational goal of ending rocket fire against the country to the narrow and more achievable goal of mapping and destroying the extensive network of tunnels that facilitate weapons smuggling into Gaza and the transportation of Hamas terrorists out of Gaza into Israel to conduct attacks.

As in previous operations, at the beginning the “single goal of [Operation Protective Edge was] to stop Hamas’ incessant rocket attacks against Israel’s civilians.” But as Israel began its ground operation, the objectiveshifted. To be sure, the I.D.F. still sought to locate and destroy caches of rockets and fabrication facilities, and to prevent launches, but these became secondary objectives to the main goal of degrading the tunnel infrastructure. The threat to Israel posed by tunnels and bunkers constructed by its adversaries is, of course, not new. In 2006, Gilad Shalit was abducted from Israel and held captive in Gaza for five years after Hamas attackers infiltrated the country via a tunnel. And during its 2006 war in Lebanon, Israel discovered an extensive network of tunnels and bunkers constructed by Hezbollah that were used to inflict significant damage on the I.D.F., a model of which Hamas surely took note. But the Israeli military’s freedom of action to pursue the destruction of the tunnels as the primary military objective of the ground operation came in large measure because Iron Dome substantially mitigated the threat of rocket strikes against Israeli cities.

This shift in emphasis, however subtle, had important consequences for the manner in which Israel conducted Operation Protective Edge. Since the start of the ground invasion, maneuvers by Israel’s military have generally been restricted to the northern, eastern, and southern edges of Gaza—predominantly where the tunnels are located—instead of in broader swaths of the Gaza Strip.

On balance, the shift in emphasis in this campaign to the narrower and more achievable goal of identifying and destroying the tunnels is a result of Iron Dome’s success in intercepting missiles fired on Israeli cities. If it is in fact true, as Prime Minister Netanyahu has said, that the I.D.F. destroyed all known tunnels from Gaza into Israel, this would be an important achievement for the Israeli military because it would have removed a significant threat to Israel—one which caused many of the I.D.F. casualties during Operation Protective Edge, and which would have been used to plan mass casualty attacks on Israeli civilians.

Finally, we can also assess the political effects of Iron Dome, the most important of which can be seen domestically within Israel, rather than in the conflict between Israel and the Palestinians. The most prominent of these effects has been to relieve political pressure on the Israeli leadership to expand the campaign beyond the limited objectives of destroying the tunnels. In this sense, the Iron Dome system is preventing the kinds of escalation that took place during previous conflicts in which rockets or suicide bombers were able to strike directly into Israeli population centers. Indeed, Iron Dome has effectively neutralized the tactic—missile strikes directed at Israeli civilian population centers—that Hamas and Hezbollah have used to great effect in previous rounds of fighting with Israel. These missile strikes were intolerable to the Israeli population and government, and necessitated more extensive military operations designed to stop indiscriminate rocket attacks on Israeli civilians. With Iron Dome accomplishing that objective in Operation Protective Edge, the Israeli government was able to protect its civilian population without a broader ground operation.

An instructive comparison is with Israel’s 2006 war against Hezbollah in Lebanon, which took place before Iron Dome was operational. During that conflict, 44 Israeli civilians were killed, primarily in rocket attacks conducted by Hezbollah that targeted some of Israel’s most populated cities, including Haifa, its third largest. In order to stem the rocket fire, Israel launched a much more extensive bombing campaign and ground operation in Lebanon, and the costs of the operation were commensurate with its scope. In addition to 44 civilians, 119 Israeli soldiers were killed. In Lebanon, some estimates put the number killed at over 1,100 (many of which were Hezbollah members), with approximately 1 million internally displaced persons.

Similarly, during Operation Cast Lead in 2008-2009, which was aimed at stemming Palestinian rocket fire into Israel, the I.D.F. began its ground operation by quickly bisecting Gaza and engaging in battles in Gaza City—a more extensive ground operation than the one that took place recently. This pattern was also seen during the height of the Second Intifada from 2001-2003, when terrorist attacks struck directly into the heart of Israeli cities. At that time, Israel responded to the drumbeat of suicide bombers by operating on the ground in the central casbahs of Palestinian cities like Nablus and Jenin, which became the sites of fierce battles as the military sought to disrupt terrorist groups plotting further attacks. In Operation Protective Edge, by contrast, the military is able to pursue the more limited aim of destroying tunnels rather than being forced by civilian casualties in Israeli cities to seek a more expansive objective. And one can get a sense of how Israel would have reacted to extensive civilian casualties from its sharp response to the rocket fire that led some U.S. and European air carriers to stop flying to Ben Gurion Airport in July.

The cost to Palestinians of Operation Protective Edge is, to be sure, staggering. But a broader operation designed in response to casualties that resulted from direct rocket strikes on Israeli cities would have been even more destructive. Thus, an important political “success” of the Iron Dome system is to have limited the campaign in a way that would have been politically difficult if rockets had been exploding in Israeli population centers.

To the extent that Iron Dome does have a longer-term effect on the political dynamics between Israel and the Palestinians, it will likely be positive. This is because Israel fears that in any future withdrawal from the West Bank, the territory would be used to stockpile and fire rockets at Israel, as happened after the I.D.F. withdrew from South Lebanon in 2000 and Gaza in 2005. To the extent that Iron Dome is an effective anti-rocket system, it can help ameliorate some of those concerns. Indeed, the development of security technologies for Israel that would mitigate risks attendant with a putative Israeli withdrawal from the West Bank in the context of a peace deal played an important role during the American-sponsored negotiations during the past year.

The Iron Dome system will not resolve the issues at the core of the century-old Israeli-Palestinian conflict: whether and how to divide Jerusalem and create secure borders; whether the Palestinian Authority will abandon the “Right of Return” or acknowledge the right of the Jewish people to a homeland of their own; and what exactly Palestinian sovereignty on the West Bank and Gaza will look like, among many other issues. But in the interim, Iron Dome has logged significant achievements on tactical, strategic, and political levels—about all that one can expect of a defensive weapon system.


Zachary K. Goldman is the Executive Director of the Center on Law and Security at NYU School of Law. He has served as a policy advisor in the U.S. Department of the Treasury’s Office of Terrorism and Financial Intelligence, and as a special assistant to the chairman of the Joint Chiefs of Staff, and also has worked in the litigation department of Sullivan & Cromwell. He has published widely on U.S. foreign policy, sanctions, counterterrorism, the Middle East, and national security law.


Photo credit: Israel Defense Forces