Slow and small, drones find cracks in Israel’s high-tech air defenses

Israel’s multilayered missile defense system, which has been adept at intercepting many of the rockets and missiles fired at population centers throughout this multifront war, is facing a new threat: nimble, slower, and often small drones.

No air raid sirens blared in Israel Sunday, when a drone launched by Hezbollah forces in Lebanon entered Israeli airspace, eventually crashing through the roof of an army base dining hall deep inside the country. The explosion killed four recruits having dinner after a day of training and wounded dozens of others, some of them seriously.

“The drones ... are one of the biggest challenges facing us in the past year,” says Zvika Haimovitz, a retired brigadier general and former commander of Israel’s air defense corps.

“We are dealing with a multidirectional threat ... and the Iranian proxies recognize the potential and the gaps” in Israel’s defenses, he adds.

Sunday’s fatal drone, one of three launched simultaneously by Hezbollah, was originally detected, and then lost for 30 minutes, during which it flew roughly 60 miles until its GPS-driven warhead hit its target. The other two were intercepted, one by Israel’s vaunted Iron Dome air defense system, and the other by the navy.

Friday night, on Yom Kippur, the holiest day in the Jewish year, a Hezbollah drone struck a building in Herzliya, in central Israel, but air raid sirens had alerted people to seek shelter and there were no injuries.

In July, the Houthi militia in Yemen, like Hezbollah a member of the Iran-funded and -cultivated “Axis of Resistance,” fired a drone that flew hundreds of miles before hitting an apartment building in Tel Aviv, killing a man sleeping in his bed.

Drones have also been fired into Israel by Iran-backed Shiite militias in Iraq and during the first-ever direct Iranian attack on Israel in April. The region is currently bracing for Israel’s response to a ballistic missile barrage from Iran in late September and, in turn, a possible counterstrike from Iran.

The retaliatory cycle could potentially plunge the Middle East even further into chaos.

On Tuesday the U.S. Department of Defense confirmed the Terminal High Altitude Area Defense system had arrived in Israel, as had the U.S. soldiers who will be operating it in the event of a ballistic missile attack by Iran.

Underscoring the urgency of such assistance, a report in the British newspaper The Financial Times said Israel’s missile defenses are short of interceptors.

Touring the army base south of Haifa that was hit Sunday, Defense Minister Yoav Gallant told the soldiers Monday that the military was investigating what went wrong and was developing new methods to address the drone threat.

Daniel Hagari, the army spokesperson, was more blunt on Sunday: “We must bring a better defense.”

Mr. Haimovitz notes that over 1,200 drones had been launched toward Israel since Hamas invaded southern Israel a year ago. Most were identified and intercepted, but 221 slipped through.

“It will never be a 100% success, but we need to fill the gaps and do much better than an 82% success rate,” he says.

Why are they such a wily weapon?

The challenges that drones pose are many, although they are a relatively low-tech weapon. First, they are slower and smaller, and fly lower than missiles, making it harder for radar systems to detect them. They can easily be confused with Israeli planes or even birds. They are built to be light, often using radar-absorbing carbon materials instead of radar-reflecting metal.

“They are also very maneuverable, able to perform complex and sharp movements in the air and go up and down and below the sight of detection systems,” says Yehoshua Kalisky, a senior researcher at the Institute of National Security Studies.

“One of the complexities of [Israel’s defense] mission is to build a picture of what one is really seeing in the sky,” Mr. Haimovitz says. “We are talking about a chaotic picture with a lot of objects and targets to decipher – helicopters, jets, interceptors, enemy rockets, and birds. And in real time you need to build situational awareness in a very busy picture.”

Intercepting a drone can also be tricky, Dr. Kalisky says, because fighter planes fly four times faster than drones, and because drones launched into Israel from as close as Lebanon leave little time for interception.

In recent years, Israel prioritized developing air defense systems, including the Iron Dome, David’s Sling, and the Arrow 3 missiles, rather than defenses against low-flying aircraft and drones. Another vulnerability: The air base targeted and hit by Hezbollah Sunday, and details about it including its dining hall, were easy to find online.

Among the new tier of systems Israel is working on that could boost its drone defenses is a powerful laser being developed by Rafael Advanced Defense Systems, an arms manufacturer owned by Israel’s Ministry of Defense.

Another solution being touted is more old-fashioned: a modern version of the Gatling gun called the M61 Vulcan, which was developed decades ago. It can shoot 6,000 rounds per minute and is radar-guided.

“We have to have a new outlook in the battlefield and accept the fact that our enemies are using relatively low-tech weapons in an effort to defeat us,” says Dr. Kalisky. “So we may have to look back and adopt the old methods.”