It is only a matter of time, writes Amos Yadlin, before Hamas attempts to send its forces into Israel via tunnels. The IDF can limit its response to occasional, circumscribed sorties into Gaza, but such an approach is likely to escalate into open conflict despite Israeli efforts to the contrary. Thus, absent a technological equivalent of the Iron Dome missile-defense system for repulsing tunnel attacks, Israel must prepare for a preemptive strike:

Operation Protective Edge proved that attack tunnels dug beneath the border of the Gaza Strip were almost the only strategic tool Hamas possessed to attain any significant gain, and most of its other so-called surprises and military efforts—long-range rockets, drones, and naval commandos—failed. . . .

[E]ventually, Hamas will force Israel into another conflict. Since, [as a general principle], a preventive strike is better [than being dragged into war on the enemy’s terms], the first question, more important than the tunnels, is: what is the objective of the future round of fighting and how prepared is Israel? . . .

Israel must establish that the discovery of cross-border tunnels ready for Hamas attacks requires preemptive action. If such action should escalate into a full-blown conflict, the conflict must be brief but forceful, based on a clear strategic objective that unlike all previous military encounters has the potential to effect a fundamental change in the balance of power and the dynamics between the sides.

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.