The Israelis in recent years have been very effective at isolating Gaza and the Palestinian territories and denying the Palestinian militants their previously effective weapon of suicide bombings through extensive security measures. Over time, the militants in Gaza have been forced to rely more on indirect fire weapons of increasing sophistication to target the Israelis. Hamas' rocket arsenal has steadily increased in size, diversity and quality over the years and now poses a significant threat to Israel.

Adapting to Israeli Countermeasures

During Operation Pillar of Defense, a few patterns have emerged in how Hamas uses its rocket capability and attempts to maximize its effects. The Iron Dome system, which is designed to intercept short-range rockets fired into Israel, has challenged Hamas' ability to inflict damage with its rocket arsenal. The militants have attempted to adapt by firing rockets in salvos in order to oversaturate the Iron Dome system. When rockets are fired simultaneously and in larger quantities, the Iron Dome battery is unable to intercept all the rockets, increasing the chances that some of the artillery rockets will strike their targets.

Another adaptation has been the use of remote control or long wires to launch rockets. The Israeli capability to strike back at launch locations with counter-battery artillery fire as well as airstrikes has forced Hamas and other Palestinian militants to change their methods to ensure the survival of the fighters launching the rockets. To Hamas, these operators are more important than the shorter-range rockets.

Fajr-5 Impact Locations map

Since Operation Cast Lead in 2008, Hamas and other militants in Gaza have increasingly sought to enhance the durability of their rocket arsenal by staging rockets in makeshift silos from which the rockets can be quickly deployed and fired. A key necessity when fighting the Israeli military and its overwhelming superiority in intelligence, surveillance, and reconnaissance assets is camouflage. The Israelis were confident that they had neutralized the majority of Hamas' Fajr-5 rockets during their initial strikes, but the recent salvos of long-range rockets fired at Israel's major cities have put that claim into question. This highlights the fact that, despite Israel's considerable intelligence-gathering capability, Hamas and other militants in Gaza have gotten better at dispersing and camouflaging their weapons.

It is also important to note that Hamas employs multiple rockets in its arsenal, ranging from the locally made Qassam rocket to the Fajr-5 currently being used to target Israel's major cities. Despite claims that they targeted Jerusalem with a purportedly locally manufactured rocket called the M-75, it is very unlikely that Hamas or other Palestinian militants have developed the ability to locally manufacture these longer-range rockets. These rockets have very likely made it into the Gaza Strip through Sinai after being furnished by state sponsors such as Iran.

Limits of the Militants' Rocket Arsenals

Despite their growing and increasingly sophisticated rocket arsenal, the militants in Gaza are still severely constrained in their employment of these weapons. Aside from the continuous threat and complications posed by Israeli countermeasures, the Palestinian militants' rocket arsenal is limited by its inaccuracy.

For instance, the Fajr-5 is really an area effect weapon. It is designed to be fired in salvos and to disrupt and inflict casualties on enemy troop concentrations rather than on single targets. Based on the Fajr-5's specifications, half of the rounds fired in a salvo will land within roughly 3 kilometers (1.9 miles) of the target at its maximum firing range. In truth, the Fajr-5 is probably even less accurate.

Militants in Gaza also are unlikely to possess the same fire control and computing capabilities as the Iranian military — the country in which the Fajr-5 was created. Calculating elevation, angles and bearing can be complicated, and given that the Fajr-5 has no in-flight self-correcting mechanism, it can easily be driven off its desired flight path by strong winds or other atmospheric variables.

Stability of the firing platform is also important. When used on its designed truck chassis transporter, the rocket can be stabilized before launch by stabilizers lowered to the ground from the truck for greater grip. Many of the Fajr-5s launched by Gaza militants are likely being fired on modified and improvised mounts that do not lend themselves to accurate firing.

This loss of accuracy has some potentially serious implications for the militants in Gaza. When targeting cities that have sacred sites, such as Jerusalem, or other Israeli cities close to the West Bank, the militants have to contend with the possibility that they may inadvertently hit their own holy sites or Palestinian land. As evidenced by today's rocket fire on Jerusalem, the Gaza militants have decided the risks are acceptable.