The clash between Israel and Hamas-backed fighters in the Gaza Strip continued over the weekend and into today, with the death toll in Gaza inching toward 100 (there were 91 recorded deaths as of Monday morning). But amid the troubling images and stark numbers trickling out of the conflict there, one set of numbers represents a rare bright spot: the number of Hamas rockets that Israel’s “Iron Dome” missile-defense shield is knocking out the sky. Scattered reports from various Israeli officials and news media suggest that Iron Dome has intercepted more than 300 rockets fired at Israeli population centers since hostilities began, or between 80 and 90 percent of rockets targeted.
As missile defense goes, these success rates are more or less unprecedented. One of the five Iron Dome batteries deployed to southern Israel reportedly intercepted a full 100 percent of incoming rockets fired during one Hamas salvo. The overall success rate has been described by various officials at anywhere between 75 and 95 percent. Calling it a conservative 85 percent success rate still puts Iron Dome in a class by itself where missile defense systems are concerned. Hitting a screaming rocket with a screaming rocket is, after all, really, really difficult.When many people think of missile interceptors, they think of the American-made MIM-104 Patriot missile interceptor system and its much-heralded successes during the 1991 Gulf War, during which then-President George H. W. Bush called the Patriot missile interceptor overwhelmingly successful, using numbers that described it as something like 97 percent effective. But we’ve since learned that those success rates were really much lower--mostly after changing the parameters of what defines a success (later analysis showed that the Iraqi Scuds that the Patriots were “intercepting” were simply failing in flight far more often than the Patriots were destroying them). The dubious success of the Patriot system has since served as a lingering reminder--in-flight missile-defense is a challenge that even the most technologically advanced military in the world hasn’t been able to overcome.