Lt. Archie Leonard, an IDF soldier, walks into a vacant house, lifts a metal grate off of the floor, and climbs down a short ladder that leads to a hidden tunnel. I follow him as he walks about 15 yards, turns right, and then clambers up a second ladder. We emerge into the ground floor of a building almost directly across the street from where we’d started. “Bang, bang,” Leonard says.Then he pantomimes firing a machine gun through the window. “They would never know what hit them,” he tells me. We’re at the Elyakim training base in northern Israel, where troops are training in a mock Lebanese village for a war that seems increasingly likely to come sooner rather than later. Just last week, four rockets were fired from southern Lebanon toward Haifa, triggering the first retaliatory Israeli air strikes against Lebanese targets in more than two years. A local branch of an al-Qaida spin-off group claimed responsibility for the attack, which provided an unsettling reminder of the missile threat growing just a few miles from Israel’s northern border.Israeli officials say Hezbollah has an arsenal of more than 60,000 Iranian-made rockets, some capable of reaching Tel Aviv. In 2006, Hezbollah fired roughly 4,000 rockets at Israel during a month-long war. Next time around, Hezbollah could fire that many missiles every two days. Lt. Col. Peter Lerner, an IDF spokesman, said at least some of the missiles would probably make it past the Iron Dome air-defense systems Israel has had in place since March 2011. “The volume of rockets would challenge the capabilities of the Iron Dome,” Lerner told me. “It would not be able to stop all of them.”While Hezbollah is currently preoccupied with helping prop up Syrian dictator Bashar al-Assad, sending thousands of battle-hardened Hezbollah fighters to help Assad reverse rebel gains and regain the upper hand in the bloody civil war there, Lerner and other Israeli officials warn that Israel remains the group’s top target. “Those rockets won’t be used against the Syrian rebels,” Lerner said. “We know where they’ll be aimed if Iran gives the directive.”Lebanon’s own internal instability also provides a safe haven for other groups that want to hit Israel. Retired Israeli Brig. Gen. Amnon Sofrin, the former head of the Mossad’s intelligence directorate and the IDF’s intelligence and reconnaissance center, said Israel will eventually have to take steps to neutralize or reduce the numbers of rockets controlled by Hezbollah and its allies. Air strikes might be able to take out a good percentage of the Hezbollah rockets, but Sofrin says that the missile sites are so well hidden that a significant number can be destroyed only by ground forces. “I believe we won’t have any option but to go back one day to deny their capability to launch rockets into Israeli territory,” Sofrin said.Which is why the IDF is ramping up urban combat training operations at Elyakim, which in the years since the 2006 Lebanon War has gone from an afterthought to a requirement for all active-duty troops. Israeli soldiers slowly wending their way through small Hezbollah-controlled villages were often ambushed in exactly the way Lt. Leonard demonstrated: Hezbollah fighters would shoot at Israeli troops from a house on one side of a street and then suddenly disappear. A few seconds later they’d open fire from the other side, leaving the Israelis confused about where their enemies were hiding and uncertain about where to aim back.The Israelis didn’t figure out until too late that Hezbollah had rigged dozens of villages with extensive networks of tunnels and underground bunkers. By the time the 34-day war came to an end, 119 Israeli soldiers had been killed and hundreds more wounded. Hezbollah, Israeli generals concede, had simply outsmarted the vaunted Israel Defense Forces. “We simply weren’t ready,” Sofrin told me. “Our training was terrible and outdated, and it didn’t prepare our guys for what they’d be facing.”***Israel spent decades learning how to fight its Lebanese enemies. But in 2000, when Israel withdrew from southern Lebanon after an 18-year occupation, the IDF took an elite unit called Egoz that had been trained to hunt Hezbollah militants in the rocky, dusty hills of southern Lebanon and redeployed it to the Palestinian territories. Egoz spent the next six years fighting in the cities of the West Bank and Gaza. When it was sent back to Lebanon in 2006, the unit was fatally out of practice and lost five soldiers in a single day of fighting in a Lebanese village less than a mile from the Israeli border. Capt. Eytan Buchman, an IDF spokesman, told me that Egoz and other Israeli Special Operations units have resumed training for potential missions into Lebanon.Some of the training at Elyakim is specifically designed to teach Israeli combat troops how to search for and destroy Hezbollah rockets. On a recent morning, I climbed a winding, rocky hill near the mock village to watch a squad of Israeli soldiers conduct an antirocket exercise. Elyakim personnel use sound effects and large bundles of fireworks to create the illusion of active combat. Shortly after I arrived, I heard the whoosh of a “rocket” made of fireworks arcing into the air, followed by an explosion that echoed off the surrounding hills. A plume of mottled smoke floated through the air like a gray balloon. Two of the soldiers standing nearby shook their heads: The explosion meant that their comrades hadn’t found all of the fake rockets in time.Later that morning, I stood in a clearing just outside the village and watched as a reserve officer from an infantry brigade ordered three of his men to gather just above the entrance to a mock Hezbollah tunnel. He told Avi, a recent immigrant from Florida, that he was going to be the first down the ladder. Two other soldiers were responsible for protecting Avi from enemy fire by lowering a Plexiglas shield—known as the Magen David—behind him as he clambered down each rung.Continue reading: “Ya’alah! Do it again!”The officer counted down from 10 and then clapped his hand against his leg, the signal for the drill to begin. Avi—who had the words “I Am My Brother’s Keeper” tattooed on his neck—jumped onto the ladder and started making his way down, but the soldiers holding the green ropes that control the Magen David didn’t quite have the hang of it. They lowered the shield far too quickly the first time, leaving Avi almost completely exposed as he came down the ladder. The next time, they lowered the Magen David more slowly, but the shield came down unevenly, protecting Avi’s left side without covering his right one. “Congratulations,” the officer told them sarcastically. “He’s only half-dead this time. Yaa’lah! Do it again.”Mock villages like Elyakim aren’t unique to Israel. Following the 2003 invasion of Iraq, the Pentagon built model Iraqi towns at a handful of Army and Marine installations to train its troops in counterinsurgency tactics. The largest and most realistic of the faux villages were built at Camp Irwin, a giant base in California’s Mojave Desert. As at Elyakim, actors playing militants fired paintball pellets and blanks at the soldiers to simulate insurgent ambushes, moved around using sophisticated networks of tunnels, and tried to kidnap individual troops. The fake insurgents at Camp Irwin used Hollywood-style pyrotechnics to simulate suicide bombings and mortar attacks against U.S. outposts. The training was so realistic that a few soldiers had their deployment orders rescinded after they showed symptoms of battle fatigue—and at least one soldier was expelled from the military after he snapped and “killed” a group of civilians.Elyakim is a minor-league version of its American counterparts. The U.S. mock villages functioned like real towns—complete with actors, many of them actual Iraqis recruited from the large expatriate community in San Diego, who lived there nearly year-round—and were so big that troops could spend weeks there. Elyakim, by contrast, is so small that you can walk through all of it on foot in less than 15 minutes. The trainers at the American villages created detailed narrative scenarios that could last for days and balance raw combat tactics with other counterinsurgency strategies, like getting to know village elders.At Elyakim, trainers try to instead make the most of the base’s small size by running different scenarios through the same buildings. Troops repeatedly practice different aspects of village fighting, like the safest ways of entering and clearing an enemy tunnel. The village contains roughly 60 one- and two-story white houses, all arrayed around a central mosque with a tall prayer tower. The roads are wide enough that units can practice moving alongside their tanks and scanning surrounding buildings for enemy fighters. The simulations also extend underground, where Israel has built exact replicas of the Hezbollah tunnels it found studded throughout the villages of southern Lebanon.“The tunnels weren’t ratlines like we used to see in Gaza,” Leonard, a spokesman for the training base, told me. “In Gaza they were made by kids digging with a spoon. In Lebanon, Hezbollah sent in trained engineers with bulldozers. The Hezbollah tunnels have concrete walls, air vents, and lighting. We’ve recreated all of that here. Our guys won’t go in blind next time.”The training personnel at Elyakim also study Hezbollah battlefield techniques so they can give Israeli infantry troops a taste of what they would encounter in Lebanon. Soldiers dressed as Hezbollah fighters fire blanks at the invading Israeli troops from the mosque and pop up out of the tunnels to ambush small groups of soldiers or try to kidnap stragglers. The simulations are designed to force soldiers to acclimate themselves to the stresses of seeking shelter or treating wounded troops amid the noise and chaos of house-to-house combat.Elyakim personnel wearing sand-colored mountain camouflage were sprinkled across the hills with orders to sporadically ambush the Israeli troops by popping up and firing machine guns packed with blanks. When soldiers were hit, they lay on the ground and waited for medics to come put them onto makeshift gurneys and carry them away. The fake Hezbollah fighters were always found and killed; in Elyakim at least, Israel always won. As I was leaving the hilltop, I noticed that one of the dead Hezbollah troops was wearing a knit yarmulke.This story was reported with a grant from the Pulitzer Center on Crisis Reporting.***Like this article? Sign up for our Daily Digest to get Tablet Magazine’s new content in your inbox each morning.Yochi Dreazen is a contributing editor at The Atlantic and the author of a forthcoming book about military suicide.