In a recent paper published by the Begin-Sadat Center for Strategic Studies, Uzi Rubin, former head of Israel’s Missile Defense Organization, discusses the significant contribution that the Iron Dome defense system has made to Israel’s security and its implications for the future. America can learn from Israel’s cost–benefit analysis for the effectiveness of the system.

Iron Dome is an anti-rocket active defense system that made its debut during the rocket attacks launched from Gaza into Israel this past April and August. Without even being declared to have initial operational capability, the system was deployed by the cities of Ashkelon and Beersheba, where it made an immediate impact.

Over the course of these two conflicts, the Iron Dome system has boasted an 85 percent success rate, according to Michael Oren, the Israeli ambassador to the U.S. With only one Israeli killed by these rocket attacks, Rubin argues that the greatly reduced lethality needs to be taken into account when assessing the success of the Iron Dome system.

Before the system was implemented, there was a rockets-per-fatality (RPF) rate of 75, with 300 rockets being fired and four fatalities. The initial lethality in the 2011 escalations was 300 RPF, which means it must have been “Iron Dome’s effectiveness that reduced the rockets’ lethality by about two-thirds.”

Thus the Israeli Defense Force (IDF), according to Rubin, concluded that the Iron Dome system had achieved its even broader strategic goals: “protecting Israeli life and property, providing new flexibility to the political leadership, and giving the IDF extra time to prepare for offensive operations.” In saving civilian lives and property, the Iron Dome system has, for Israel, redefined the cost–benefit analysis of missile defense.

Taking into account other factors beyond being cost effectiveness at the margin is one lesson Heritage believes we can learn from Israel. It costs Israel over $100,000 for each Iron Dome Tamir interceptor, many times more than it costs Hamas or Hezbollah to produce the rockets they used in the April and August bombardment. But by taking into account four other factors, the Israelis have shown how it is extremely cost effective to deploy the Iron Dome system in the field.

The Israelis have found that the value of what is being defended far exceeds the cost of the interceptors. The force-on-force comparisons demonstrate that, with Hamas’s inaccurate rockets and Iron Dome’s advanced trajectory systems, the Israelis can determine if a rocket is going to hit a target of any value and as such have needed to intercept only about 20 percent of launched rockets. The system illustrates how missile defenses give military and political leadership more options that can offset the cost of escalation.

Lastly, it is important to remember the intangible benefits the system provides, such as peace of mind and the ability to break the will of the enemy.

The Iron Dome system has shown that the relative cost effectiveness of offensive and defensive systems is an elaborate undertaking, but it is not a simplistic calculation. Iron Dome’s success demonstrates how an active defense, when done right, can be worth the costs.