Extensive Hamas Tunnel Network Points to Israeli Intelligence Failure

Israel launched its bloody offensive in Gaza to stop Hamas from lobbing missiles at major cities like Tel Aviv. The biggest challenge to the vaunted Israeli army, though, is coming from the ground, not the air: a sophisticated network of Hamas tunnels that have surprised Israeli security officials, caused a huge number of military fatalities, and struck fear into the hearts of many ordinary Israelis.

Israeli military, intelligence, and political officials have known for years that Hamas fighters were burrowing into their country from Gaza through underground tunnels. An Israeli army spokesman said this month that the military had discovered four tunnels just in the past 18 months, well before Israel’s current ground offensive began. But in interviews, current and former Israeli officials said the military and intelligence services didn’t realize the extent of Hamas’s subterranean operations, nor did political leaders act to counter a threat that has become the central focus of Israel’s Gaza campaign and stands as potentially the biggest Israeli intelligence failure in years.

A senior Israeli official, speaking on condition of anonymity, said the military has so far discovered far more tunnels — 40 and counting — than Israel had previously thought existed. The number came as a surprise, as did the sophistication of the tunnel network. Current and former officials said that Israeli intelligence and political leaders knew that the tunnels were fortified with concrete and had space to store weapons and food. But Israeli intelligence analysts and political leaders didn’t comprehend that the tunnels were wide enough to move several Hamas fighters into the country at a time, and they didn’t realize how many of the tunnels ended up in Israel, particularly near civilians. (A Hamas video that shows fighters emerging from a tunnel and attacking an Israeli military installation provides a vivid example of why Israelis have so come to fear the clandestine attacks.)

"Of course we didn’t know all the details and how complex was the network below the ground. I don’t think we had the full picture," said Giora Eiland, a retired major general in the Israel Defense Forces (IDF) who served as Israel’s national security advisor from 2004 to 2006. "But I would emphasize that we did not fully understand the operational consequences of the use of tunnels by [Hamas]."

Eiland said that Israeli intelligence knew the locations of some tunnels, but that analysts didn’t understand some key details such as the strength of the concrete used to build the tunnels. That’s important for knowing what it would take to destroy the tunnels, understanding how they could be used to store rockets and explosives, and knowing whether the tunnels are wide enough to accommodate large numbers of fighters. All these technical details were crucial for predicting whether Hamas was likely to use the tunnels to launch aggressive strikes inside Israel, Eiland said — which is just what Hamas has done.

While most public attention has focused on the large and growing casualties from the Israel Defense Force’s military campaign in Gaza, a debate has been roiling in Israel in recent weeks over exactly what the military and intelligence services knew about the existence of those tunnels and how big a threat they posed to the country’s security. It portends a political reckoning over intelligence failures once the ground assault eventually wraps up. That day may not come anytime soon: Israeli Prime Minister Benjamin Netanyahu used a televised address Thursday, July 31, to tell his country that the current offensive will continue until the tunnels are destroyed, despite the mounting international pressure to call off the assault. So far, Israel has lost at least 59 people, including 57 soldiers, while the Palestinian death toll has climbed to at least 1,370.

"Without a doubt, the full extent of the tunnels was not discovered until the ground operation began" in early July, said Jonathan Schanzer, vice president for research at the Foundation for Defense of Democracies. The number, the complexity, and the sophistication of the tunnel network took Israeli forces by surprise, Schanzer said.

A U.S. intelligence official, speaking on background, acknowledged that the tunnels are more numerous than the Israelis originally thought. He wouldn’t comment about the American assessment of the total number of tunnels or whether it differs from Israel’s. But he said that American analysts had concluded that the use of tunnels to launch attacks inside Israel marked a new development in Hamas’s military tactics. As to whether that could have been predicted, the official declined to speculate.

But Israeli officials knew as early as 2006 that Hamas could launch operations from the tunnels, operations that are strikingly similar to the ones Hamas conducts now. In June of that year, a group of fighters emerged from a tunnel hundreds of meters long and came up behind an IDF position. There, they captured the young soldier Gilad Shalit and took him back into Gaza. Hamas held Shalit in captivity for more than five years; he was finally released in exchange for more than 1,000 mostly Palestinian and Arab-Israeli prisoners held in Israeli jails.

The year after Shalit was captured, Israel’s comptroller issued a scathing report blaming top military officials for an "ongoing failure" to close the tunnels. The report cited the military’s "flawed handling of the threat" and recommended deploying technology that could give the government early warning and provide intelligence to troops in the field, according to the Jerusalem Post. Such a system was never fully developed.

More recently, there have been ominous indications that the tunnels were more extensive and sophisticated than previously thought. Israel understood that tunnels from Gaza posed a "huge risk" as early as October 2013, when the IDF discovered a long tunnel underneath the kibbutz Ein Hashlosha, just east of the border with Gaza, Col. Grisha Yakubovich, the head of the civil department in the IDF’s Coordination of Government Activities in the Territories, said in an interview.

The tunnel was enormous: It ran 1.5 miles, 66 feet below the ground. Authorities estimated that some 350 tons of concrete were used to build it, enough to build a small hospital three floors high, Yakubovich said. "We were amazed by the size of it."

Hamas went to extraordinary lengths to hide construction of the tunnels from Israeli intelligence and military forces. In a scene straight out of the classic film The Great Escape, fighters emptied bags of flour — humanitarian food aid from the United Nations — and then used them to remove dirt from tunnel construction sites, Yakubovich said. Whenever Israeli air forces saw the bags on the surface, they assumed they were food deliveries, not evidence of Hamas secretly building an underground infrastructure. "This was a very clever way to make sure the IDF would not fire upon them," Yakubovich said. "Hamas exploited international goodwill to hide terror activities."

Five months after the discovery of the tunnel under Ein Hashlosha, in March 2014, the Israeli military unearthed yet another tunnel coming from Gaza. Photographs showed that it was fortified with concrete and wired for electricity. With every new discovery, Israel tried to close off the tunnels it found, but the military launched no comprehensive assault on the entire network. Nor did Israeli intelligence understand that the tunnels found so far were merely a fraction of the total number.

Schanzer said that the March discovery alerted Israeli security officials about "the beginning of a trend," in which Hamas fighters would come to rely on the tunnels to launch ground strikes on Israeli villages and military positions. Schanzer said that he spoke to senior Israeli officials in early July, before the ground assault began, and they were worried that there were more tunnels than had previously been counted. But again, the government launched no comprehensive plan to counter the tunnel threat.

Even if the government had, though, it’s debatable how successful the operation would have been. Using surveillance aircraft, including drones, Israel can obtain near-total, round-the-clock awareness of what’s going on at the surface in Gaza, tracking vehicles and people as they come and go, said Eiland, the former national security advisor. But that doesn’t tell intelligence analysts what’s happening under the ground in the tunnels, sometimes 60 feet deep. As a result, "a lot of information was missing" about the extent of the tunnels and how many of them there were, Eiland said. "We knew, but we did not really understand, the level of threat that they actually posed." Eiland added that even a few months ago, before the latest operation in Gaza began, he would not have considered mapping out and closing tunnels to be as high a priority as stopping rocket fire from Gaza.

Israeli leaders have considered other means for countering the tunnel threat by trying to sense what’s happening below ground. About eight years ago, the Israeli government, defense contractors, and universities began developing a comprehensive system that would use fiber-optic cables, buried at shallower depths than the tunnels, to detect movement in the soil. Microphones could also be used to capture acoustic signals and help intelligence analysts pinpoint the location of tunnels.

But despite what Eiland said are the "dozens of millions of dollars" that have been spent on research, the system has never materialized. Nor, he said, has there been as much urgency to build the system as there has been for Iron Dome, the comprehensive missile-defense shield that aims to intercept and destroy rockets fired at Israel. There’s not likely to be a viable tunnel-detecting system in the near future. "We certainly don’t have anything close to [Iron Dome] with the tunnels," Eiland said.

That leaves Israeli intelligence to continue scouring Gaza mostly from the air, using drones to build a so-called "pattern of life" of the movement of suspected Hamas fighters. Watching their comings and goings, analysts can get a better read on where in Gaza Hamas is placing the entrances to tunnels — often inside buildings, security experts said, which the air forces can then attack.

Israeli officials are especially sensitive to allegations of intelligence failures, and not just because the tunnels have added a new, terrifying dimension to Israel’s long battle with Hamas. Many experts regard the 1973 surprise attack by Egypt and Syria on Israeli positions in the Sinai Peninsula and the Golan Heights as a case study in intelligence breakdowns. Israel prevailed in the ensuing Yom Kippur War, but it sent the clearest signal to date that the country could no longer be ensured of militarily dominating its rivals in the region. The war also threatened to bring the United States and the Soviet Union into military conflict, as each side stepped up efforts to supply their respective allies with arms.

Costly intelligence failures have continued. In 2006, Hezbollah forces in Lebanon launched an anti-ship missile at an Israeli warship, the INS Hanit, which was patrolling waters off the coast of Beirut. The ship stayed afloat, but four crew members were killed. An IDF investigation concluded that "as far as the intelligence picture is concerned, it was found that despite the lack of pinpoint information about the weapon in the hands of Hizbullah, there was information in the Navy in the past that could have lead [sic] to some type of an assessment that the enemy holds shore-to-ship missiles."

It’s impossible to draw conclusions about the total effectiveness of any intelligence system based on individual failures, however acute. But, as in the United States, a pattern emerges in which Israeli intelligence seems to broadly understand a threat, but lacks the specific details for knowing when, where, and how an adversary might strike.

The lack of such precise intelligence doesn’t preclude a preemptive strike against a known, potential threat — which is what the Hamas tunnels have been for years. So, why didn’t Israel launch a more aggressive effort to close known tunnels and then find others to which they were connected? It’s possible that politics wouldn’t have allowed it.

"Imagine what would happen if we initiated an operation like this and we began a war out of the blue against Hamas in order to prevent this kind of threat," Eiland argued. With Israel already under international pressure to end its assault on Gaza — which has claimed at least 1,370 lives, most of them civilians — and political leaders well aware that Israel’s last military foray into Gaza brought international condemnation, the potential threat of attacks from tunnels might not have been sufficient motivation for the country’s leaders to act. They’ll eventually determine whether that was a wise decision, after the latest round of fighting concludes and Israel asks itself how the war could have been prevented.

Kate Brannen contributed reporting.