EIGHTY-FIVE-year-old Yisrael Brauner, a founding member of Kibbutz Kissufim in southern Israel, was taken by surprise on October 30.“We’d just finished eating lunch when a series of loud explosions shook the house, the windows especially. Not just one, but a few,” he recalls.Shortly afterwards, the members of the western Negev kibbutz, situated just two kilometers from the Gaza Strip border, received cellphone messages that the IDF had detonated a tunnel from Gaza and there was nothing to worry about.Brauner said, on further reflection, that the incident was to be expected.“Everyone knows they’re digging tunnels. The fact that they found one and did what they did – we’re very happy,” he says.The IDF described the attack tunnel as a “grave and unacceptable violation of Israeli sovereignty.” The subterranean threat originated in the southern Gazan city of Khan Yunis, crossed under the border and was detonated inside Israeli territory adjacent to the border fence.Some 32 tunnels were discovered during the 2014 war, including 14 that extended into Israel. Two other tunnels have been demolished by the IDF since the end of the war (also known as Operation Protective Edge) but both of those were old tunnels that the Israeli forces had failed to destroy during the 30-day conflict. The IDF believes the tunnel destroyed near Kissufim was built after 2014. Prime Minister Benjamin Netanyahu said Israel’s enemies should not test Israel – not at sea, in the air, on land or underground.“I told you that we were working on breakthrough technology. Today we located a tunnel and destroyed it. The first responsibility of any government is to look out for the security of its citizens. Anyone who tries to attack us – we attack them,” he said.Islamic Jihad, supported and financed by Iran, built the tunnel with the aim of kidnapping Israelis to exchange for Palestinian security prisoners held in Israeli jails. At least 10 of the 14 people believed killed in the Israeli demolition belonged to the terrorist organization, two were senior Islamic Jihad military commanders and two were Hamas fighters.Israel denied it had deliberately targeted the people in the tunnel. It is believed that most of the fatalities occurred after the blast, from secondary explosions and collapses and smoke inhalation. Israel also categorically denied Palestinian accusations that it had injected poison gas into the tunnel.Six days after the tunnel demolition, Israel announced that it had recovered the bodies of five missing Islamic Jihad gunmen who were buried in the rubble. Earlier, Israel had refused a request by the International Red Cross to allow the Palestinians to search for the missing bodies inside Israel’s self-declared Gaza buffer zone.“The bodies of the five martyrs will not remain for long in Israel's hands. We know how to recover the bodies of our people,” Islamic Jihad said in a statement. “The campaign continues and will not end.”Israel is seeking the return of three civilians, two of whom are mentally challenged, believed held captive by Hamas after crossing the Gaza border, as well as the bodies of Oren Shaul and Hadar Goldin, two soldiers killed in the 2014 war whose remains have not been returned to Israel for burial.“Until we get back our dear ones, they won’t get the body of even one terrorist,” Public Security Minister Gilad Erdan said in a statement. A senior official with the IDF’s Southern Command said the operation was ongoing.“We still have decisions to make. Islamic Jihad was dealt a serious blow and it deserved it. We won’t apologize for it. We’re ready for any scenario. Something can happen here at any moment.”The Kissufim explosion represented an impressive victory in Israel’s ongoing struggle to counter the Gaza tunnel threat. Utilizing state-of-the-art technology, the army was able to monitor the construction of the tunnel and act once it crossed the border, destroying the threat with precise explosions deep underground.According to some observers Israel has now established itself as the leading nation in developing technology to combat subterranean threats, similar to what it has achieved in the past decade in developing an answer to the missile threat posed by its enemies.An IDF commander in charge of the effort to thwart the tunnel threat told Yedioth Ahronoth that the Kissufim operation was not a random success.“We integrate technology, operational capabilities, intelligence and engineering capabilities in a way that allows each to complement the other,” he said. “The folks on the other side are beginning to realize that they’ve got a problem. They realize that their tunnels won’t be usable. We’ll create a completely different balance of terror in the subterranean world, and our challenge is in the very deep reaches, not in the shallow depths. We’re on our way to bypassing the enemy.”Hamas and Islamic Jihad have made no secret of the fact that the ongoing construction of new attack tunnels remains one of their top priorities with massive financial and manpower resources channeled to such projects. Two weeks before the Kissufim incident, the United Nations Relief and Works Agency (UNRWA) discovered a tunnel built under one of its schools in Gaza.Jason Greenblatt, US President Donald Trump’s special envoy, sharply criticized Hamas, tweeting that the Palestinians in Gaza deserved better.Islamic Jihad, which is not party to the reconciliation agreement signed between the Palestinian Authority and Hamas earlier this year, threatened to avenge the Kissufim explosion and the IDF deployed additional Iron Dome anti-missile batteries and went on heightened alert along the Gaza border. However, despite some weekend protests close to the Gaza border fence, the week after the incident was quiet.The Kissufim incident occurred just days before the Gaza border crossings were handed over from Hamas to Palestinian Authority control as part of the Palestinian reconciliation process. Egypt, which brokered the historic deal, reportedly made it clear to Hamas that it would not tolerate any military response, fearing an Israeli retaliation and an escalation that could torpedo the entire reconciliation deal.Hamas is reluctant to open a fourth round of warfare with Israel at this juncture. Diplomatically isolated and cash-strapped, it desperately needs the economic improvement in Gaza it hopes the reconciliation will bring, including the reopening of the Rafah border crossing with Egypt, scheduled for mid-November. Israel, for its part, also made it clear that it did not seek escalation.Despite the Islamic Jihad threats, all indications were that the de facto cease-fire between Israel and Gaza, in place since Operation Protective Edge, will hold. Except for sporadic rocket fire, usually from small jihadist or Salafist groups, the three years since the war has been one of the quietest periods ever for the Gaza periphery, encouraging the arrival of thousands of young families who have relocated to the area. To maintain the quiet, Israel has refrained from carrying out targeted killings or initiating offensive activity in the Gaza Strip.Israel is currently engaged in building a massive underground barrier along the entire length of the Gaza Strip border in one of the country’s biggest-ever infrastructure projects. The work is on schedule but will take about another year and a half to complete.The hope is that once the barrier is in place the subterranean border will be hermetically sealed, eliminating a major threat to the Gaza periphery. Until then, Israeli leaders have promised to act decisively every time an offensive tunnel is discovered.