During the 2006 conflict in southern Lebanon, about 25% of the Hezbollah-fired missiles struck populated areas in northern Israel. In the current conflict, while Israeli security is keeping a lid on where the Hamas and Jihadist missiles have landed, the very few deaths reported in Israel—in the single digits—indicate that the first five batteries of the short-range, Iron Dome missile defense system are surprisingly efficient.

The Second Lebanon War, as Tel Aviv calls it, amounted to 14.7 billion shekels ($3.8 billion) in damage and costs. Since then, Israel has invested 300 million shekels in research and development to stop that 25% of missiles, say officials at Rafael, Israel’s primary missile developer. The investment is to help ensure that Israel does not have to invade Gaza again. The cost of a day of operations inside Gaza is 1 billion shekels, they say, more than the cost of the missile program.

Israel funded the first two batteries of the Iron Dome system, which was developed by Rafael Advanced Defense Systems (missile and launcher) and Israeli Aerospace Industries (radar). The U.S. is funding another eight batteries in exchange for access to and a stake in the technology. Raytheon and Rafael have teamed to market Iron Dome and the more sophisticated David’s Sling intermediate-altitude air defense missile.

“We’re collecting data from every [enemy missile] launch to look for improvements,” says a Rafael official. “We are already upgrading the system. We predict the success rate of missile intercepts will be better than 90%.” Israeli Defense Forces (IDF) statistics in the latest round of missile attacks so far show an 85% intercept rate.

As a backup plan, the Israeli government authorized mobilization of 75,000 army reservists. However, the reservists are seldom used for tip-of-the-spear combat operations. They backfill units while special ops, paratroops, armored forces and specialist units like tactical air and artillery support are used as penetrating forces.

In the first two days of the Hamas missile attacks, Nov. 14 and 15, the IDF counted 877 rockets fired toward Israel. Of those, 570 landed in Israel and 307 were intercepted by Iron Dome.

However, the 570 that were not intercepted and hit Israel does not mean Iron Dome failed. It means the system’s ability to determine which missiles are headed toward populated areas—and which are not—is working as designed. At about $60,000 per missile (estimates range from $50,000 to $90,000), the Israeli defense ministry saved about $3.4 million by not firing.

The downside to the Iron Dome equation is the need to ensure that Hamas and other foes cannot saturate Israeli defenses. Therefore, “we need a big inventory [of Iron Dome missiles], and this is what is expensive,” a Rafael official says.