In a speech given the day after the death of Abu Bakr al-Baghdadi—the “caliph” of Islamic State (IS)—President Trump stated that Iran had been “right there” in fighting the Sunni terrorist group, along with its allies Syria and Russia. The comment echoed a common refrain of the Obama administration; in fact, the former president proposed in his 2014 letter to Supreme Leader Ayatollah Ali Khamenei that Washington and Tehran join forces against IS, their common enemy. While Iranian troops and proxy militias did occasionally fight IS, writes Tzvi Kahn, partnering with Iran would have been the equivalent of “hiring the arsonist to put out the fire.”

Iran’s efforts to achieve hegemony in the Middle East have entailed the brutal suppression of Sunni Arab populations. In Syria, the relentless atrocities of the Assad regime reflected those of IS itself. In Iraq, a pro-Tehran government marginalized Sunni Arabs and persecuted their leaders. So long as Iran’s expansionist policies remain unchecked, terrorists like Baghdadi will exploit the Sunni-Shiite conflicts that Tehran specializes in fueling.

It didn’t have to be this way. After the fall of Saddam Hussein in 2003, Iran-backed Shiite forces began to infiltrate and co-opt the new [Iraqi] government, enabling Tehran to exert substantial influence in Baghdad. In response to the massacres of Shiites by Sunni insurgents, [Iran-backed] Shiite militias unleashed death squads of their own and planted roadside bombs that killed hundreds of U.S. soldiers. Fortunately, the surge of U.S. forces in 2007, coupled with a new counterinsurgency strategy, gave Iraq a second chance to overcome its divisions. But the Obama administration’s hasty withdrawal of troops in 2011 reversed this progress, resulting in another downward spiral of sectarianism.

The U.S. completed its exit from Iraq only months after the onset of Syria’s civil war, which not only created another haven exploited by IS but also spurred Iran’s military intervention to save the Assad regime. Iran opposed IS in Syria but was more concerned with other rebel groups, both secular and Islamist, that posed a more immediate threat to Assad. Meanwhile, Assad’s brutality—about which Iran had no qualms—led Syria’s Sunni population to cooperate with IS and other extremists as a desperate means of self-preservation. . . .

If President Trump is serious about defeating radical Sunni Islamists who loathe the West as much as they do their regional enemies, then he needs to recognize who America’s friends and enemies are. Islamic State grew out of a sectarian war that Tehran has backed. If Washington fails to check Iran, Sunni jihadism is likely to endure.

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.