The former Soviet republic of Azerbaijan has become one of Israel’s closest allies, and its friendship remains unshaken by the Gaza war.

The majority Shiite nation of Azerbaijan is the biggest supplier of oil to Israel, which reciprocates by selling sophisticated arms including missile systems and drones. While the flow of oil in exchange for advanced weapons is the backbone of the alliance, a confluence of interests is propelling the former Soviet republic on the Caspian Sea closer to Israel, often in defiance of discontent at home and dismay among neighbors Iran and Turkey.

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.