While Islamic State (IS) formally claimed responsibility for only one of the deadly terror attacks that have struck Paris, Nice, and Vienna in recent weeks, Shiraz Maher sees its influence manifest in all of them. And even if Europe is no stranger to the group’s depredations, Maher detects a troubling pattern in the current spate:

There is a common thread that links them all: the new and dangerously innovative ways IS now identifies its targets. From its earliest days, around 2014-15, the group advised members to select targets that would cause maximum offense and outrage. Within Syria and Iraq, for example, the group regularly desecrated churches and other religious and cultural heritage sites, such as the ancient city of Palmyra.

All of this informs its broader strategic view—that there is a cosmic battle between Islam and everyone else; between “truth” and “falsehood.” The group’s own literature, including a ten-page editorial in its online magazine Dabiq in 2015, has described the need to “destroy” what it calls the “gray zone,” [which poses] an existential threat to [IS’s] extremist dogma that preaches a Manichaean world of dark and light, good and bad, Muslim and infidel.

Attacks such as those we have seen in France and Austria are designed to eradicate the gray zone. Their aim is to polarize populations, undermine any sense of the common good, and hasten a civilizational crisis.

Groups such as IS are, for now, beaten and in retreat. Their territorial control in the Middle East and ability to command support on the ground in foreign capitals is severely degraded. But what endures is the power of their ideas to entice young, disaffected Muslim men, and the terrible chaos that ensues from that.

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.