12/13/2012 - 18:15

Iron Dome: Behind the hoopla, a familiar story of missile-defense hype

Subrata Ghoshroy

Subrata Ghoshroy

Ghoshroy is a research associate at the Massachusetts Institute of Technology's Program in Science...

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Since an Israeli-Hamas ceasefire was announced in November, Israel's Iron Dome system has been hailed as proof that missile defense has emerged from the realm of the theoretical and assumed the status of a real battlefield weapon. It's also been called a game changer for the Israel-Palestine conflict. The verdict is in, crowed Max Boot, a defense expert at the Council on Foreign Relations in New York: "Missile defense works."

But behind press reports on the supposedly spectacular success of Iron Dome -- which the Israeli government claims shot down more than 400 rockets launched toward Israel from Hamas-controlled Gaza during recent hostilities -- lies a murkier story.

Two decades ago, US military officials trumpeted a similar success story in the 1990-1991 Persian Gulf War, claiming that the Patriot system fielded by the US Army intercepted nearly 80 percent of the Scud missiles launched by Iraq toward Israel and Saudi Arabia. When the available data on the Patriots' performance was later studied, the claims were found to be largely false.

When all the information on its performance is ultimately gathered, reviewed, and shared with Israel's defense partners, including the United States, Iron Dome may well prove to represent a step forward in defense systems of its type. At this point, however, one fact is abundantly clear: Israel seems to have shared little information to date, and so there is no way for observers outside the Israeli defense forces to know how successful Iron Dome actually was.

Not a missile defense system or a game changer. First, let's debunk the myth that Iron Dome -- even if as successful as advertised in the Gaza conflict -- constitutes proof that missile defense, writ large, works. Terminology is important here. Iron Dome is primarily a rocket defense system, and rockets are fundamentally different from missiles. Rockets do not have a guidance system; missiles do. Rockets follow a trajectory that is determined by the position and angle of the launcher and the propellant. So, once they are fired, and the radar detects their launch, they are easily tracked. Tamir -- Iron Dome's interceptor missile -- has its own small radar, which provides final guidance toward the target rocket and its warhead, before the interceptor ignites its own payload near the rocket. The resulting explosion creates a shrapnel cloud that, if successful, punctures the rocket warhead, which explodes several kilometers high in the air.

While destroying a rocket in this way is a great technical feat, it is not the "hit to kill" system on which the US missile defense effort has been premised, and the Iron Dome system is not intended to work against larger ballistic missiles. The US Army has deployed in Iraq a system called Phalanx, which has reportedly stopped similar rocket attacks to the Green Zone, a section of Baghdad that houses a massive US embassy and offices of the Iraqi government. Press reports indicate that Phalanx could have done the same job in Israel. Strangely, the success of the Phalanx has been barely mentioned in the press. Neither has it been acclaimed as the harbinger of future missile defense systems. So why is Iron Dome different? US taxpayers -- who have supported Iron Dome with hundreds of millions of dollars, with hundreds of millions more possibly on the way -- need to know.

The jury is still out on more sophisticated systems -- including David's Sling, Arrow, Terminal High Altitude Area Defense, and the Ground-Based Midcourse Defense programs -- that the United States and Israel are developing with larger and faster missiles in mind.

But it is clear that even if one accepts the Israeli claims of success at face value, Iron Dome was not a game changer for Israeli citizens. Hamas has launched thousands of rockets over the last several years to terrorize people living in Sderot, Ashkelon, and other border towns. Although they have resulted in an occasional casualty, most have done little or no other damage. But they have succeeded in disrupting the normal lives of citizens, which is the primary intent. During the November hostilities, citizens continued to hunker down in bomb shelters; no one could take the chance that a rocket might leak through the Iron Dome and strike them.

Paying for the Iron Dome. The Iron Dome system is particularly not a game changer if one considers its economics. The cost of operating Iron Dome batteries in the latest conflict was reportedly between $25 million and $30 million -- to intercept some 400 rockets. (Hamas is said to have launched more than 1,400 rockets, many of which travelled harmlessly toward uninhabited areas.) The Israel Defense Forces have estimated that nearly 200,000 rockets point at Israel from its various enemies -- Hamas, Syria, Hezbollah, and Iran. The vast majority of them are cheap, short-range rockets like those launched by Hamas in November.

The cost of one Iron Dome interceptor is about $50,000; the battery that fires the interceptor costs $50 million. In comparison, the Qassam short-range rocket favored by Hamas costs less than $1,000. One does not have to be a rocket scientist to figure out how the economics stack up, generally.

Over the last 20 years, US taxpayers have been paying a good part of the costs to develop a multi-layered missile defense system in Israel to counter a variety of rocket and missile threats. Iron Dome has reportedly received $275 million from the United States so far, and there is another $600 million in the defense bill for 2013. Israel's military estimates that it will need nearly $4 billion to provide nationwide coverage in terms of rocket and missile defense. It would need serious help from the United States to meet such a need.

The next layer of the Israeli system is known as David's Sling, which is supposed to counter faster and longer-range missiles fired from Lebanon or Syria. It is also jointly funded by the United States. While the amount of US subsidy for David's Sling is not readily available, press reports indicate that in 2010 and 2011, the United States contributed about $160 million.

The final layer of the foreseen Israeli system consists of the Arrow, which is also a joint US-Israel program; it is designed to intercept long-range ballistic missiles launched from, among other countries, Iran. Washington has paid more than half of Arrow's $3 billion development cost in the past decade and has committed to fully fund developing Arrow-3, the system's latest upgrade, the estimated cost of which is $100 million. An Arrow-3 interceptor missile will have a price tag of $2.2 million.

How did the Iron Dome really perform? The reported success of Iron Dome appears to be generating interest in other countries, with Brazil, India, Singapore, and South Korea among those described to be interested in acquiring the system. That supposed success also seems to have been conflated with proof that missile defense in general works. NATO is deploying Patriot batteries in Turkey to intercept Syrian missiles. And missile defense true believers are pushing lasers again, even though billions of dollars have been spent on failed attempts to build lasers that reliably shoot down large missiles. For example, Raytheon is advertising a "Laser Phalanx" as the weapon system of the future that could replace everything in the tactical battlefield from Iron Dome to the current Phalanx system, used by the Navy and adapted as a land-based system that has been called extremely effective in stopping rocket attacks on the Green Zone.

This enthusiasm for missile defense -- and particularly laser missile defense -- glosses over decades of expensive failure. Like Israel, the United States has aimed to produce a layered system, including land- and sea-based platforms that will intercept incoming missiles in various phases of trajectory -- boost phase, mid-course, and terminal phase. The cumulative sum spent so far is about $200 billion. Yet, there are still major challenges to fielding an effective system.

Given this history, there are two important questions that need to be answered before Congress authorizes additional funding for Israel's Iron Dome system. First, how did Iron Dome's performance compare with the Phalanx's, also produced by Raytheon. Israel was reportedly in possession of a Phalanx unit; whether it was pressed into action is not known.

The second question focuses on the success rate of Iron Dome itself.

Although very little data is in the public domain, some analysts question the 90-to-95 percent intercept rate advertised by the Israeli military. The Israelis need to be forthcoming with Congress, providing data to back up the claims of such an astronomical success rate. There should also be independent investigation of those claims.

In a recent conversation, MIT professor and missile defense expert Ted Postol suggested one approach for such investigation: the examination of video footage of Iron Dome intercepts. The Iron Dome's interceptor employs a blast fragmentation warhead. During an intercept attempt, the shrapnel from the explosion of the interceptor is supposed to hit the threat rocket and blow up its warhead. Each of these explosions creates a spherical fireball that is visible in a video shot. The fireballs could be seen as elongated, rather than spherical or in some cases as two distinct spheres; they could also overlap, distorting their spherical shapes.  But, Postol says, if the video showed a single fireball sphere, it would most likely be an indication of a failed intercept.

One can hope that commercial video footage will be available in coming days so a somewhat independent assessment of the Iron Dome intercept rate can be made. Whether or not that is possible, Congress needs to have hearings to examine the data that is available and evaluate its impact on the US missile defense program. The history of missile defense is littered with claims of success that later turned out to be untrue. The US government shouldn't spend money making the Iron Dome into a Golden Dome.