Since Tuesday, Palestinian Islamic Jihad (PIJ) has fired hundreds of rockets into Israel from the Gaza Strip. Hamas, which rules Gaza, seems to have avoided joining in, adhering to the strategy of low-level conflict it has pursued since autumn 2014. To Hillel Frisch, the current round highlights the differences between the two terrorist groups:

While Hamas views the use of violence as a means for increasing the volume of trade with Israel and securing the inflow of Qatari money, both of which enhance the welfare of its hardcore supporters and of the Gaza population at large, Islamic Jihad seeks full-fledged confrontation as part of an Iranian strategy to deflect attention from its Syrian military buildup and regional expansion.

These strategic goals reflect the differences in the political and organizational makeup of the two terror groups. A Sunni organization with popular support that is clearly identified with the wider Muslim Brotherhood movement, Hamas operates like fish in water in a society that is almost exclusively Sunni, with most of its members being truly devout. If there are any Gazan Shiites, they keep their beliefs and practices strictly to themselves.

There is a world of difference . . . between Hamas and Islamic Jihad, which is known for its strong links to Iran and which has no popular base. Though they value PIJ for its sacrifices, most Gazans suspect its members of being Shiites in disguise. A form of love-hate relationship thus prevails between the general population and PIJ, a disposition that has become more pronounced as the conflicts between Shiites and Sunnis in Syria, Iraq, and Yemen have intensified.

[But] Islamic Jihad’s paltry popular base means its dependence on Iran is all the greater. For [one thing], the organization can operate purely as a fighting arm without the need to take into account the welfare of the Gaza population. [Moreover], Hamas cannot afford to bring an immediate end to the rockets. [It] can only constrain, rather than stop, PIJ because it needs Iran as well.

On Tuesday, a Hizballah drone attack injured three people in northern Israel. The next day, another attack, targeting an IDF base, injured eighteen people, six of them seriously, in Arab al-Amshe, also in the north. This second attack involved the simultaneous use of drones carrying explosives and guided antitank missiles. In both cases, the defensive systems that performed so successfully last weekend failed to stop the drones and missiles. Ron Ben-Yishai has a straightforward explanation as to why: the Lebanon-backed terrorist group is getting better at evading Israel defenses. He explains the three basis systems used to pilot these unmanned aircraft, and their practical effects:

These systems allow drones to act similarly to fighter jets, using “dead zones”—areas not visible to radar or other optical detection—to approach targets. They fly low initially, then ascend just before crashing and detonating on the target. The terrain of southern Lebanon is particularly conducive to such attacks.

But this requires skills that the terror group has honed over months of fighting against Israel. The latest attacks involved a large drone capable of carrying over 50 kg (110 lbs.) of explosives. The terrorists have likely analyzed Israel’s alert and interception systems, recognizing that shooting down their drones requires early detection to allow sufficient time for launching interceptors.

The IDF tries to detect any incoming drones on its radar, as it had done prior to the war. Despite Hizballah’s learning curve, the IDF’s technological edge offers an advantage. However, the military must recognize that any measure it takes is quickly observed and analyzed, and even the most effective defenses can be incomplete. The terrain near the Lebanon-Israel border continues to pose a challenge, necessitating technological solutions and significant financial investment.