July 10, 2013: Israel is making preparations to deploy a sixth Iron Dome anti-rocket battery this month, with two more coming within the next eight months. Iron Dome is the principal defense against short range rockets fired from Gaza or Lebanon. Iron Dome has a range of 70 kilometers against rockets, as well as artillery and mortar shells up to 155mm. Work is underway to increase Iron Dome range to over 200 kilometers. Meanwhile, Iron Dome remains a controversial mix of battlefield success and controversy.

For example, the Israeli military has had to keep repeating public reminders that the Iron Dome anti-rocket system was not meant for defending towns and villages but military bases and critical infrastructure (power and water). This reminder comes after Iron Dome successfully defeated a Hamas attack (using 1,500 rockets) last November. Many Israelis assumed this meant they could expect similar protection if there were a larger attack from Hamas or Hezbollah. But the military points out that Hamas has over 5,000 rockets and Hezbollah over 40,000. If one or both of these groups fired several thousand rockets, including longer range (over 20 kilometers) ones, the Iron Dome batteries would have to be used to defend military bases and power plants first (otherwise defense of the nation would be imperiled) before trying to cover civilian targets. With a smaller attack the existing number of Iron Dome batteries is sufficient to defend everything, which is what happened last year. But until it is possible to buy more Iron Dome batteries, a major attack will leave many civilian targets vulnerable. With eight batteries available next year, there will still be a need to concentrate on protecting key targets if there is a major attack. The military believes it would need twenty batteries to cover everything but it is unclear if the government can come up with the money for that. The U.S. is supplying some of the cash for this but not enough for another dozen batteries.

The military has been pointing this out for over three years. The first mention was in response to announced plans to keep the new Iron Dome batteries in storage. At that time politicians were making much of using Iron Dome as a means of defending civilians living close to the border and vulnerable to rockets fired from Gaza in the south and Lebanon in the north. But it turned out that it takes about 15 seconds for Iron Dome to detect, identify, and fire its missiles. Most of the civilian targets frequently under fire from Gaza are so close to the border (within 13 kilometers) that the rockets are fired and land in less than 15 seconds. When longer range rockets are fired there are many more targets (civilian and military) to aim at and Iron Dome is much more effective. This is what happened last November, when Hamas fired many of its longer range rockets at larger towns and cities deeper in Israel.

This explains why, after Iron Dome was declared ready for action three years ago, it was surprisingly (to most Israelis) placed in storage. The air force said they would prefer to save money and put the Iron Dome batteries in storage, to be deployed only for regular tests and training or, of course, for an actual emergency (an expected large scale attack on southern or northern Israel). Politicians demanded that at least one battery be deployed along the Gaza border. Eventually, all the batteries were deployed to defend a constantly shifting array of targets. Moving the Iron Dome batteries a lot is good training and confuses the enemy. Meanwhile, the military sees Hamas and Hezbollah stockpiling larger numbers of longer range rockets that would enable massive use of long-range rockets against military bases (most of them more than 20 kilometers from the Gaza or Lebanese borders). The generals believe it's more important to protect the military forces, who ultimately defend Israel, and that's what Iron Dome will now be used for, at least when there is threat of a major rocket attack.

Since 2010, Israel has bought eight batteries of Iron Dome anti-rocket missiles. Five are in action and were responsible for defeating the Hamas attack last November, which used a lot of long range rockets. Each battery has radar and control equipment and three missile launchers. Each battery costs about $50 million, which includes 50-100 Tamir missiles (costing $50,000 each). Iron Dome uses two radars to quickly calculate the trajectory of the incoming rocket and do nothing if the rocket trajectory indicates it is going to land in an uninhabited area. But if the computers predict a rocket coming down in an inhabited area, Tamir guided missiles are fired to intercept the rocket. So far Iron Dome has been able to intercept 85 percent of missiles it identified as heading for an inhabited area. The latest version of Iron Dome has a longer range, as well as more effective fire control.

This approach makes the system cost-effective. That's because Hezbollah fired 4,000 rockets in 2006, and Palestinian terrorists in Gaza have fired over six thousand rockets in the past eight years, and the Israelis know where each of them landed. Over 90 percent of these rockets landed in uninhabited areas, and few of those that did hit inhabited areas caused casualties. Israel already has a radar system in place that gives some warning of approaching rockets. Iron Dome uses that system, in addition to another, more specialized, radar.

The Palestinians are believed to have tried to defeat Iron Dome by firing a lot of long range missiles simultaneously at a few cities. In theory this could overwhelm one or two Iron Dome batteries. But Israel is able to keep 24/7 UAV watch on Gaza and spot attempts at large scale simultaneous launchers. This enables Israel to bomb many of the launch sites. This results in many rockets destroyed on the ground or launching erratically and landing within Gaza or nowhere near where they were aimed. Because Iron Dome can track hundreds of incoming missiles, quickly plot their trajectory and likely landing spot, and ignore the majority that will not land near people, the Palestinians tried putting hundreds of larger (long range) missiles into the air at the same time to be sure of causing lots of Israeli casualties. So far the Palestinians have not been able to get enough rockets into the air at the same time to make this work. They may never get this to work because they would have to hide preparations for the simultaneous launch of many rockets and this is very difficult to do undetected.

The Palestinian rocket attacks have been around since 2001, but got much worse once Israel pulled out of Gaza in August of 2005. This was a peace gesture that backfired. From 2001 to 2005, about 700 rockets were fired from Gaza into Israel. Since the 2005 withdrawal over 5,000 more rockets were fired into Israel. The rate of firings increased after Hamas took control of Gaza in June, 2007. In 2011, 700 rockets and mortar shells were fired, this jumped to 2,300 in 2012, when Hamas briefly went to war with Israel. The retaliation was so effective that Hamas agreed to a ceasefire. Thus, during the first half of 2013, only about 40 rockets and mortar shells landed in Israel.

Hamas has been bringing in more factory made Iranian and Chinese made BM-21 and BM-12 rockets. Hamas revealed last November that they had brought into Gaza factory-made BM-21 rockets, each with a range of 20-40 kilometers. They also have a lot more shorter range (six kilometers) Russian designed B-12 107mm rockets. The 122mm BM-21s weigh 68.2 kg (150 pounds) and are 2.9 meters (nine feet) long. These have 20.5 kg (45 pound) warheads but not much better accuracy than the 107mm model. However, these larger rockets have a maximum range of 20 kilometers and a flight time of under 15 seconds. Again, because they are unguided, they are only effective if fired in salvos or at large targets (like cities, large military bases, or industrial complexes).

There are Egyptian and Chinese BM-21 variants that have smaller warheads and larger rocket motors, giving them a range of about 40 kilometers and flight time over 15 seconds. Israel found that there are now dozens of even larger Iranian Fajr rockets, with a range of 70 kilometers, plus several hundred extended-range (40 kilometers) 122mm rockets, and even more standard range (20 kilometers) 122mm rockets in Gaza. Before last November there were thought to be over 10,000 rockets stored in Gaza. But between Iron Dome and attacks on storage sites by artillery and smart bombs, over half of those rockets were destroyed.