The Tunnels of Gaza

You're listening to the Urban Warfare Project Podcast from the Modern War Institute at Westpoint. I'm John Spencer, chair of Urban Warfare Studies at MWGY and host of this podcast. Today's topic on the podcast is the Tunnels of Gaza. I won't have a guest today, it will just be me, two weeks back from Gaza City in Gaza, but also looking back at what do we know about the Tunnels of Gaza, what were the challenges they presented, what were the IDF adaptations, doctoral changes, equipment changes, approaches changes, and so what. So let's get into it. Yes, I just got back from Gaza City where I did an in-depth discussion about the status of the tunnels that we know it. Of course, if you want to know more about the tunnels or tunnels in general, there's two podcasts. I have one called Underground Warfare 101, another one called What Can the IDF Do About Hamas Tunnels? That was October of 2023, if you can believe it. I've also written multiple articles, post my Gaza research trips. I've now been to Israel seven times since October 7, six times embedded with the IDF inside of the Gaza Strip. And each time, of course, my research was what's the status of tunnels, what are the known knowns, known unknowns, you know, that crazy terminology. But if you look back at my articles on the urban warfare project, you'll see multiple articles, December of '24, October of '24, January of '24, October of '23, where I'm reporting on what I'm learning about the tunnels in Gaza, the challenges, the evolutions, the paradigm shifts, and that was one of my last ones, Israel's new approach to tunnels, a paradigm shift in underground warfare. But with this last trip, I learned so much and had almost even a deeper appreciation of how much the IDF has been doing to evolve, adapt, and discover, map, destroy all the tunnels. But let's go back to the beginning. So, Gaza's tunnels aren't the first, they're not the only, but they are the most unique. They're not the first, right? Ancient warfare has tunnels. Even in Israel, you have Bar Coba revolt tunnels where the Jewish rebels hid for years from the Roman Empire. American history, you can go back to the Civil War, the battles of Petersburg and other ones, World War I, of course, World War II. In Vietnam, the US military faced lots of North Vietnamese and Viet Cong tunnel networks, parts of the Ho Chi Minh Trail are underground. You have the tunnels of Coo Chi, big problem. Lots of tactics were evolved and some real cool training videos you can find online about the evolution of tunnel rats, both the American and Australian, sending guys down, destroying them, putting tear gas in them. It's a whole thing and since I specialize in urban warfare and you can't separate the urban from the underground, I've done a lot of work on the underground and you can look for that. But even today, again, Gaza's not the only people that have invested, although Gaza's are very unique. In China, there's said to be thousands of miles. So, some report 3,000, 4,000, they call it the great underground or the underground Great Wall. Of course, North Korea, even more so ever since 1950, really, North Korea has been investing in tunnels. There's estimates of over 6,000 or 8,000 shelters, but I mean, there's three underground air bases, multiple secret underground naval bases, command centers, you name it, North Korea is just full of them. Even in Ukraine, with my research, if you're a listener of the show, if you've seen my writings in Ukraine, when Russia's illegal invasion, the Ukrainians sought refuge in the underground, like in Kiev and other places. And even as that war has evolved, tunnels have been a big part of it. You even have Russian forces trying to crawl through gas pipes to infiltrate Ukrainian defensive lines and help the cities they hold. And of course, today in the Middle East, you have Hezbollah's tunnels in southern Lebanon, Syrian deep-barried plants that have been a part of the really conversation and operations. Of course, Iran with the nuclear sites underground and other tunnels, even the Houthis, freaking Houthis in Yemen, have invested in tunnels because there is protection you can get from tunnels in military warfare. And I recommend people in order to protect or even to take a guerrilla warfare, the tunnels that we're in, like the Battle of Manila in places that gives you the advantage to move, covered, and concealed. Lots of advantages. But let's talk about Gaza. Finally, Gaza's tunnels are very unique. Hundreds of miles of tunnels built underneath every civilian area on purpose. Of course, there are some in the rural area, but underneath the cities, they created cities underneath the cities for the sole purpose, for military purposes. And it's one of the first war, and I wrote this in an article, where the subterranean matters more to the enemy force than the surface. As a matter of fact, the surface is being used as a shield and as a sacrifice. But the underground is the major ways in which they believe they can achieve victory, mainly through the delayed defense time aspect of how challenging it is to deal with tunnels. Of course, that's also where they had the hostages, that's where the Hamas leadership was. They conduct their planning, their rocket supplies, deep buried rocket manufacturing plants have been found underground. And it is hard to explain if you haven't walked the ground like I have, or of course others, IDF soldiers, others. Anywhere I went, if you took a step, it is more likely, it doesn't matter if you're in the open area of a natural corridor or deep in Gaza City, like I was recently, every step you took, it was more likely than not, there was a tunnel underneath you. And that really changes a lot of the military tasks. If you go back to listen to that underground or subterranean warfare 101, I think it was called underground 101. Gaza's tunnels are very unique. And I hope that we never see it again. Even Lebanon's cross-border tunnels or the Hezbollah used their tunnels to stage equipment, to do their tactics. Yes, they built them under houses and they put missiles in houses, but that wasn't the primary investment to put them underneath every structure, every house, every mosque, every civilian apartment complex. And there are different types of tunnels that we'll talk about. I used to say that Hamas, in my research, dug these tunnels using the law fair that they do in human shielding underneath every school and everything. In the development of Gaza, though, in many areas, they built the tunnel and then put the school or whatever it was on top of it. But the tunnels in Gaza are also not new, right? You can go back to the, I mean, if you want to start in 2000s, even before Israel disengaged 2005, I presented in Israel back in 2016 about tunnel bombs that Hamas and other terrorists were digging tunnels underneath IDF locations in Gaza and then packing them for explosives and blowing them up, which is something that we saw ISIS doing in Syria and Iraq in the late 2000s during the fights for ISIS. But if you go back, Hamas had some tunnels as part of their asymmetric fighting, even the other insurgents. There's been a lot of tunneling between Egypt and Gaza and Egypt in 2015 did a counter-terror operation where they filled all the tunnels full of sewage, water and sea water, hoping to destroy, but they also displaced the civilian population because all the tunnels, these smuggling tunnels and terror tunnels for Egypt's stability were under houses and everything. So they very controversially displaced all the people, filled all the tunnels and thought they had achieved some success. And this is kind of one of the points is you can trust, but you have to verify. In Israel's history, though, more recent, there was a period when there was what they call the secret tunnel war, where Israel knows Hamas is digging tunnels towards Israel and especially with the cross-border tunnels into Israel. And then Israel would find them, then strike them, whether they did it with evolutions of bunker buses, which we can talk about, which is also the advancement of counter-tuttle is to get better bunker buses to penetrate the ground, which also causes the enemy to dig deeper. Of course, Gaza, why is one of the many reasons Gaza is so pervasive in tunnels is because the geology is very conducive to digging in the sandy terrain until you get closer to the ocean. Then you have a water table issue, but it's very conducive to digging. So that's one of the many reasons. So you have this secret tunnel war going on for years where Israel would use all their forms of intelligence, find out there's a tunnel being invested in and towards summer popping up in Israel, and then they would strike them or move forward to destroy them. There's even early investments in Hamas once Hamas used the power 2008. Later, but even the first Gaza war, you had Hamas digging a tunnel towards Israel to condemn an Israeli soldier, Gilad Shalit in 2006, that causes major operations and eventually with rockets as well. You lead into the first Gaza war, which we wrote a case study for the modern wars to highly recommend it. So you push forward and then you have more operations, more tunnels being found, and then you have Operation Protective Edge, which is into Gaza again, focused on the tunnels. And you start learning about the heavier tunnel investments by Hamas in Gaza. And then here's where you start to get the estimates of the cost, because even in 2014, they find three tunnels that they estimated cost $90 million to produce. And you really get a picture of the amount of investment that's going in. By my estimate, over a billion dollars. So many analysts are using $275,000 per kilometer as how much it costs to dig a tunnel. But not all the tunnels are the same, which we'll talk about. There are so many different varieties of tunnels, where if you have a massive two-mile-long tunnel like they found after October 7th, that led right up to the wall, you could drive trucks through it. Ventilation, of course, that's a multi-million-dollar tunnel by itself. So over a billion-dollar investment, but back to the timeline. You also have Operation Northern Shield in 2018, where Israel discovers hezbollah tunnels being dug into Israel. And they find, I think it was 6 or 7, and they use wet cement, which is really key as in the evolution of how do you find a tunnel, depending on what type the soil is, and Israel is already leading the world in counter-toweling technologies, and acoustic types of devices, radar, and things like that. And this is back in 2018. But the Operation Northern Shield is really a bit of a history of the Israel tunnel evolutions, let's say. Then you have the key moment of Operation Guarding of the Walls in 2021. I actually visited right after that, and me and my colleagues from the Model 1 Institute got a lot of briefings about the tunnels and the rockets, of course, but the tunnels and Gaza. The entire operation was kind of short, I think, or two weeks. But it was focused on the tunnels, and there's a lot of reporting. I actually found an article where the IDFs thought they had gotten 20% success of destroying the tunnels. Some people say they saw IDF reporting at 50%. There's an article, actually, with the IDF spokesman saying they got 60 miles. Of course, later it was revealed that none of that was true. And then you could look into why it wasn't that true. But the IDF had used thousands of bunker-busting munitions and had had very little effect, actually, in destroying tunnels. There's actually captured documents after October 7th revealed that Hamas learned from Operation Guardian of the Walls, and Yaya Sinwar actually authorized $225,000 to be invested in blast doors in the tunnels in Gaza. Because during Guardian of the Walls, there was some, because if you have a bunker busser that penetrates the ground, its purpose is, of course, to hit that spot, but also to send the concussion down the tunnel, and it can collapse the tunnel. There's actually a really big New York Times article. During Operation Guardian of the Walls, Israel hit a known tunnel spot, and it rippled down the tunnel in a building that wasn't being targeted to collapse because of that tunnel. So Yaya Sinwar approves the actual emplacement of a lot more blast doors to reduce that effect, despite the fact that, actually, the Guardian of the Walls had little impact. And you had, of course, Hamas intelligence saying that maybe you did 2% of our tunnels after 2021. Interesting timeline is 2021 is also where public information is being produced that Israel had finished its underground wall. So Israel, unlike even the American southern border, has an underground wall because of the threat of tunneling, although we do have a problem tunneling anywhere we put a wall up in the southern border. There is a tunneling problem, and they do find tunnels in Texas and Arizona, other places. In 2021, though, you have reports that Israel has finished the, they call it the iron wall, which is, of course, you have the surface wall, which everybody remembers from October 7th, but it had an underground portion that went basically all the way down to the water table, which is always key in tunneling as well as the water table, and it had sensors on it that not only project if you're tunneling at that point, but even farther out, it was a big part of the, again, the tunnel warfare. As if you know, there's a tunnel, and effectively they had finished that project very costly, but very effective and stopped, which weren't used at all in October 7th. Anyways, but stopped any cross-border tunnels coming in Agaza. Now, there was an estimate of the tunnels, which becomes very key because I get this all the time at John. How many tunnels are there? How much has been destroyed? There were estimates in 2021. You know, it's actually both from the Israel sources and from Hamas sources. It's actually some Hamas leadership that has some interviews and their estimate. We have 500 kilometers of tunnels, and that's, you have the idea also giving the same estimate publicly, who knows what that's on purpose, but that's about 300 miles of tunnels. Now, that in of itself is massive, right? That's longer than most nations metro systems, the New York Metro, the Seoul Metro, the London Tube, mind the gap, all of it, but that estimate was wrong. So, let's get into post-October 7th. Hopefully, I've given you a timeline of somewhat of an evolution of, yes, of course, there is the issue of Israel knew they were digging, but they had stopped the cross-border digging and containment strategy. A person guarding the wall in 2021 is an important kind of storyline point of you've gotten it all wrong to include the estimate, you know, over a billion dollars, of course, that they had invested, and I'll shock you with the estimates that we think, not we, Israel and IDF have believe are present there based on now two years of engagement in the environment, but not all the environment. So, just remember at the time of this recording, there was 15%, about 15% of Gaza that is the IDF forces never went into, although they do have intelligence, even in those areas. The central camps, parts of Gaza City, they didn't touch where there are more tunnels, but there is no estimate, and I've for some reason become normal to say there is no number, but there is no estimate. Okay, October 7th, though, the invasion of southern Israel, the IDF ground invasion starts a couple weeks later, and then you have the issues with the tunnels, right? So, you have what capabilities does Israel have at this moment? If you walk through that whole history of Israel dealing with tunnels for years, decades, actually decades, Israel was the most prepared military in the world for underground warfare, and that's why you can look at my research, and it goes back to doing research conferences, visiting Hezbollah tunnels, Hamas tunnels, training tunnels. Israel was the most prepared. It's the only army I know of that had an entire brigade of special forces engineers. It's called the Yahlom Weasels that are analogous to the Tunnel Rats of Vietnam, but just a different scale. An entire brigade that is training, manning, and equipping research and development for underground warfare. There's a 10-year plus year counter-tunneling cooperation with the United States and R&D, and if you listen to my past podcast, you know that in the underground, everything you need, you need everything special. Nothing that you use for surface works. It's more like if you have a boat on the ocean, but you try to go underground. Underwater, you need all special equipment. Everything you need to shoot, move, communicate, conduct aid, command and control, protection, everything is different underground. You can't fire your weapon unless you have a lot of ear protection, usually dual protection. You can't know navigation system, no GPS, works underground. You have to have special navigation, no communication, no satellite, no line of sight. You can't command and control forces if you have a casualty. You have all the contaminants. You have soldiers, best soldiers in the world going underground. Then you have claustrophobia. You can get vertigo. You can lose track of time, direction, distance, awful area. But Israel had the only brigade-sized formation for years. I've said that before and published it, but I also want to point out that since the IDF, its military, have been facing this challenge for so long in so many different areas of its small geographic region. There's tunnels in Judea, Somalia, West Bank as well, but the combat engineers. I like to talk, of course, about Yahlom, the special forces within the engineering unit, but just the regular IDF combat engineers, geologists and everything, are the most prepared, most experienced at dealing with tunnels, which we really get into the task. Now, on the flip side, of course, Hamas are, at this point, master diggers. Not only can they dig tunnels at cost, so it's an occupation for many. You can do it with hand tools in most many areas. They use a very similar bracing of concrete reinforced slabs on the side with the common arching. Most Hamas tunnels are five meters tall, three meters wide, narrow passages, but they also have these very specific, sophisticated tunnels. You found Chinese boring machines. Of course, some of the tunnels had had very advanced architecture. You would need a lot of outside help. Hamas had used the tunnels throughout its entire military development. They had used its tunnels both for offensive purposes. If the IDF came from 2008 on, when they entered, they had to face the tunnels. They evolved their defensive capabilities of what they put underground. Of course, the fighters, but then they figured out how to put their rockets underground. Like I said, manufacturing plants underground, the leadership's underground. They have luxury tunnels for their leaders in conunists, other places. Around, if I didn't mention, 2014, the IDF really starts to invest a lot with Unit 9900 and other units to map the tunnel networks and what they do or don't know using all forms of intelligence. We really get you to the task. If you go back to my Underground Warfare 101, you get to what is the task of the military unit when they encounter the underground? Of course, in Gaza, since the operation is about destroying military formations, like I retrieving the hostages, which are underground, making it very hard to conduct operations, killer capturing, the leadership, and the vastness of the tunnel network. I guess I can go ahead and talk about that here, is that these tunnels, originally believed on before October 7, 300 miles, it evolves to about 450 mile estimate later, if you see through my research, and everybody's looked at how that's not possible with John. The Gaza Strip is 25 miles long, 5 to 7 miles wide. How do they have 400 miles of tunnels? They do. For many reasons, it's in layers, but also, which I'll talk about in a minute, the typology. You have lots of different types of strategic tunnels for invasion, for smuggling along the Gaza-Egypt border, which they found over 100 there once you could drop trucks through. You also found tunnels in Gaza in layers. You'd have a tunnel, earth, another tunnel. These tunnels, because of the evolution of bunker-bussing munitions, also go deeper and deeper into the ground. Just underneath almost every structure, every building down to over 200 feet underground. When you get down to that level, there's no bunker-bussing you can get to. A 2,000-pound bunker-busser might get you 35 feet. Israel is very effective at what they call drilling, and they've done that for Hadhran Nasrallah in Lebanon, Mohammed Sinmar in Gaza, where they drop one bunker-busser, drop another, and they just drill down to the maximum of that bunker-bussing capability. We saw it, of course, with the American bunker-buster at the Fordo site, where you drop multiple, and there's a way to do that. It's a whole science, but that's how they get so many. If they started mapping it in 2014, but there's severe limitations. Although, like I said, even 2018, they're advancing the technologies or engaging the world with how to do this, with the radar, how to detect things in the ground. You can detect all kinds of metals and all kinds of materials you can detect in the ground with certain types of devices. Of course, you have radar, but radar bounces off of metal. There's issues there. Human intelligence being, and as I visited the Gaza Strip, still was very big. Just by, if you think about the spider webs of tunnels, human intelligence became one of the greatest factors, but it's also document intelligence, signals intelligence. An enemy force captured telling you, "You might want to go back and look in that area because there's just layers of earth, rubberized buildings, and finding it extremely difficult." Although, one of the most effective ways, which I actually saw being done in Lebanon, is drilling. Literally drilling a small hole into the ground, and then putting a camera with radar and sensors into the ground all the way down to the water table. We'll talk about how much you do it, but if you know where there might be a tunnel, you can start drilling. I visited an engineer unit in Canunas while the battle was around them. The military tasks, though, of locate. That's all forms of intelligence. I've seen the most recent graphic of the tunnel complex, and it, of course, is classified, but it's very shocking. Even though I had been in the natural encoder, there is no estimate, but there was an estimate of over 5,000 tunnel shafts by early 2024. You can guarantee it's 10,000 or more tunnel shafts, but every shaft would have to be exploited, mapped, all these other things. Of course, if you go back to Yehalom, like I said, on October 7, Yehalom, that Special Forces Engineer Unit, has all the world's best tactic, techniques, procedures, technologies. They have the robotics that are necessary, you know, fly a drone. They have the dogs. Some people believe that all dogs can go underground. That's not true. You have to specially train a dog and the work rest ratio. Lots of videos, though, since October 7, of putting the dogs in certain tunnels to put a camera on them and to be, because the threat of IEDs in Hamas' tunnel. Another thing that Hamas did, which has similarity, like the Viet Cong and the Vietnamese, North Vietnamese, booby trapping in tunnels, but Hamas, up that game, they would pour the concrete in a lot of their tunnels and put the le bomb in the wall, inside the concrete, and all you have to do is prime it and leave, and it's booby trapped. But locating, mapping, and let's go through the task, right? So the doctrinal task, if you went to ATP3-21.51, Subtraining Operations for the US Army, Decent Book. Based on this podcast, I think there could be a lot added to it, which is the so what. But in there, it has the task of locate, map, control, contain, isolate, interdict, neutralize, clear, and destroy tunnels. I added a maneuver, and I'll tell you about why in a minute. But if you just think about each one of those tasks, you'll need different types of equipment, different types of trained forces. You might even think about the challenge different, but your task goes along with the mission, depending on what the mission was. It evolved, of course, locate, hostages have always located the enemy leadership, like was being done, early on as well, that are in the tunnels. I added a maneuver, because eventually, the IDF do a transformation. But let's talk about that. Okay, so October 7th, Israel has this prepared of this force, the yellow alum, yellow alum, over a brigade size force, you know, 4,000 and 6,000 highly trained special forces engineers. But the scale of the problem, right? If you just believed 400 miles of tunnels, 10,000 shafts or 5,000 shafts, you still haven't. And that's immediately what the IDF went into in late 2023. They, of course, in their assault, they go around some of the heaviest of Hamas's defenses, but Hamas is still in the tunnels. And the tunnels become a momentum halting obstacle, right? Because what do you do with the tunnel? You can't go past it, although I did in 2023 report about this neutralizing device that the IDF had seen years ago, which is a dual compound, big plastic bag that you pull the strip, mix the compound, throw it down the opening of a shaft, not the entire shaft. And it formed a very industrialized foam to seal the tunnel move forward. But that aside, and they called it the Spongebob bomb, or the Spongebob. It's a little funny the history of, watch what you say in big media. But the, clearly in the operations with the maneuver units, finding tunnels halting the momentum, because you had to address it, let alone the guerrilla warfare that Hamas, of course, immediately starts implementing. And like I said, they have the Hamas rockets are inside the tunnel, still launching rockets from within tunnels that they can use on rails, things like that. They're using the tunnels, of course, for the guerrilla warfare offensive tactics of hit and run, but it's all part of that strategic, that strategy. But also the tactics of just creating more time and space for their ultimate goal, which is what we saw, the information operations, and the use of the hostages and every every element, it's all resting on this underground that they're using pretty effectively in the beginning. So the IDF are halted at each shaft, basically, so they had split the hall home, just like anybody else would have, you know, given it out to the maneuver units, you have a squad, or even a team of special forces engineers, you find a tunnel, although they did have, when you find a tunnel, you bring up the specialist, he or she investigates, and you know, starts to process, exploit, map all of these functions, although they did have, they lost soldiers in the beginning, even around the tunnel openings for the booby traps, despite the specialized units. And they really ran into the limited resources of not just those special soldiers, but the limited robotics, limited dogs, they went through, they lost a lot of dogs over 29. I think it's over 30 plus now. It's also a culture thing at the end of the beginning, having visited Israel multiple times, you know, a normal reserve or infantry force is not going to go in a tunnel unless it's, you know, there's, there's a reason to basically like a soldier being captured, there was that kind of battle drill aspect of it. But there is a cultural hurdle there too. So you early in the war, you see the IDF struggling with the momentum halting that the tunnels are doing. And they immediately, because they, I wrote another article about how they're pushing lesson learned down and how they did that with learning officers and everything, they immediately starts to push down the information about tunnels. So they took what was a special task and had to push it down to the general soldier level. So it's the general purpose forces and you see that happening. During this time, you also have, which is very famous as well, Project Atlantis is what they called it, where the IDF tried to bring in five industrial pumps and the pump sea water and fresh water, both from the Israel side and from the sea, the Mediterranean sea side, pump water into the tunnels with these massive industrial pumps that can fill like an Olympic swimming pool in like five minutes and start pumping the water into the tunnels. And it does not work is they proved, you know, they had a viable idea. They experimented in combat with it and it proved not to be not to work. You know, for the purpose of tunnel, the tunnel is not a solid tube. So the water just seep out some of the tunnels because of the water, closer to the water table, they had drainage in them. It clearly didn't doesn't destroy a tunnel if it's braced with cement. Just by every means of what they wanted the water flooding to do, it didn't work. Although, when I visited a unit in, I think, I think it was in December 2023, very localized, they had some success with once they after two weeks of flooding a company level tunnel, they finally saw Hamas in buildings and could engage them in buildings because they had had a two week in a certain area of Gaza, two weeks of operation and very limited Hamas engagement because they were just going from tunnel to tunnel. The way that Hamas was arrayed across the Gaza Strip, five brigades, 24 battalions, each with four, four companies, each company had their own tunnel network, battalion, brigade. Israel is starting to learn at this point too, within each area, how was the underground, how was it dug for that company? Where were the connectors from the companies to the battalion? Where were the connectors to the battalions to the brigade? And this is what one of the things that the IDF creates mid-war that they did not have before is basically a typology of tunnels. And this is why when people start talking about macro tunnel numbers, how much has been destroyed, John, is that not all tunnels are of the same purpose or value, priority, everything. You have strategic tunnels, if you think about the invasion tunnels, these multi-million dollar, two mile long tunnels, or the operational level tunnels, which give Hamas the freedom of maneuver, which becomes a really big goal for the IDF all along the wars to cut that freedom of maneuver. Before October 7th, you could enter in northern Gaza, let's say, Erez or up near Zikim on their side or whatever, you could enter northern Gaza and from the tunnels come out in Egypt. That's how interwoven the tunnels were. So in order to cut the operational maneuver, Israel really focused on some of those connecting tunnels. So they had three that went below the Wadi Gaza, which is a river basin that separates northern Gaza from southern Gaza, and other connecting tunnels that connecting the brigades specifically. But of course, you have other tunnels that are strategic to the military faction of Hamas. You have command and control bunkers. You have leadership extravagant bunkers with air conditioners and everything in them. You have command and course command and control. You have the rocket bunk tunnels. They even converted some of the tunnels into hostage prisons, basically. So they installed bars in them, and that's where they kept hostages. So the normal you missonado US military doctrinal typologies by category. You have a category one, which is a natural forming tunnel cave, natural cavity, tunnel two, an urban subsurface system, like a metro, or a category three, which is a military-purposed underground facility. I mean, I guess all of this 400 plus miles, until I tell you otherwise, is a category three. It's just expansive, but the idea to develop this typology. So you have project Atlantis is stopped, it's a failure. The typology is being developed. And then, which I wrote about in by 2024, again, the mission matters. So the mission being to find, if you think February 2024, Yaya Sanmour, and the other Hamas leadership that are using the tunnels for operations and maneuver and everything. But also, and I met a commander in Canunis, a central Gaza, that had watched what had happened earlier in the war with the momentum stopping aspects of the tunnels and said that he refused to let that happen. I wrote a whole article about that paradigm shift that he does, how he does it, to the point where they aren't using that momentum of find a tunnel. Hamas is already gone. He's booby-trapped it. Now you have even more momentum stopping to deal with if the IDF developed a way of understanding which tunnels were which in the environment they were working in by Hamas activity and all forms of intelligence. And then getting into the tunnels before Hamas knew you were there, so the threat of IEDs is less. But also, one of the first in underground warfare history, especially modern history, is that the IDF, through this unit 98 Division General Gulpis, got high-risk operations cleared by literally the IDF's chief of staff to conduct maneuvers using the enemy's tunnels. So they had commandos and special forces entering the tunnels at the same time they were launching maneuver brigades on the surface. So simultaneous maneuver, really maneuver warfare on using the subsurface and surface at the same time, coordinated by a hire and we in the article I try to talk about how did you command and control an underground unit and a surface unit, all figured out they were doing it in combating the guerrilla warfare aspects of Hamas in those areas. Fast forward, you know, and of course the IDF, all in this process is destroying what tunnels they can. I want to hold how to destroy a tunnel because it becomes, it still is, the real strategic challenge even if Hamas was to disarm today. The military infrastructure is one of the goals and this there is a thing and with military infrastructure, and especially underground, is leave behind capability. So even if you were to defeat this enemy, you leave behind these military built, purposed underground, the next unit will use them and it's really important that they're destroyed and anywhere the IDF were, that was a big goal of the unit on top of, you know, looking for the hostages, killer capturing Hamas, you know, was destroying the infrastructure in this prioritized list. As the war continues, of course, you know, the leadership starts to be killed, Ya'ayah Samor, Muhammad Samor, Muhammad Def, all of these guys, there's ceasefires, there are pullouts go back in, there are evolutions, there are host tunnels found under hospitals where Muhammad Samor was found, the European hospital complex in a tunnel, then you're dealing with those tunnels in different ways, all along mapping the network. So as we get farther closer towards the end is, okay, what is the tunnel network now? Based on mapping for two years, not just what you thought were the locations of tunnels, but mapping it based on being present on that terrain, using all these technologies to include drilling. And I mentioned drilling earlier is that if you think there's a tunnel somewhere using human intelligence or any other form, map it, you know, all these other, you name it, then you drill down to the water table. Thousands, over 9,000 drills with about a 50% success rate or something like, the numbers aren't as important. I did find it fascinating that to be sure in Gaza, to be sure that there is no tunnel, you have to drill. So in very sensitive areas, like the buffer area right beyond Israel's previous border, ensuring that there is no one, because there were tunnels that had stopped like that, a res tunnel that I was in, which was a two mile long tunnel, 200 meters outside of, you know, into Gaza, beyond Israel's wall, drilling for that and really interesting along the Egypt Gaza border, you had to do, the idea had to do statistical drilling. So basically drilling every seven meters for that entire 10 mile stretch to make sure and to be, you know, trust but verify, verify there are no tunnels, which is critical, defeat an enemy, but also just having secure borders to know that there is no tunnel there and using your other technologies. So the mapping has been done so that John Spencer is very, is that the 500 kilometer, 600 kilometer estimate is completely wrong and is more likely than not to double that. And that's really hard, going to be hard to convince people that there's 600, 700 miles of tunnels, but the mapping that's been done for two years, the work that's being done, which ones have been destroyed, which really gets you to, even if, again, where we're at with the war right now, how do you destroy a tunnel, which is very lightly addressed in US military doctrine. And some of the, all of this podcast is about understanding an environment. And we always did this in the urban operations planners course that we run with the 40th ID was, okay, if you have an environment that you know there is a significant subterranean, go back to China, North Korea, anywhere that they've done a lot of investments, so what? Okay, it's a planning consideration. Okay, I'm going to need certain capabilities and there's reach back and I'm going to need certain knowledge, I'm going to sort of talk about mapping capability and this mapping capability, the IDF has, I've never seen it before. Then you could go to like, well, you know, can I use it for maneuver? Can I, you know, what does, what's the plan, strategic operational and tactical, if we know there's a subterranean, of course you know there's one in Gaza, and it matters to any force, especially a stabilization force going forward. The challenge of how do you destroy a tunnel has been fascinating to me. I talked about, okay, so there's, there's a few ways the IDF can destroy a tunnel or anybody and I actually do remember the Vietnam ways, you know, of using, I mean they have videos of, you know, the soldiers just throwing two grenades down the tunnel opening, which clearly doesn't destroy it, it neutralizes the opening as much as that foam bomb does, but the engineers had line charges they could do and then of course the the tear gas was about flushing and you could also, there's something called mapping where you can, you know, put something in a tunnel, water, smoke, whatever, and it pops out and that that's how you're doing the mapping. Some of that, especially with the water, was helpful in Gaza, but to destroy a tunnel, there's only a few ways the IDF have found. They have a liquid explosive, it's nothing classified, it requires you to drill into the ground every certain amount of distance a lot actually and then drill and then put the liquid explosives and explode it all the length of the tunnel. The least preferred, but we've seen it because through this evolution I talked you through, there was also really important intelligence in tunnels, right, so there's been, I saw even recently the Hamas leaders memo on the October 7th attack, a recent podcast, really explaining what was in this, like four or five page memo written by Yahya somewhere himself about why they wanted to capture so many horrific videos, how they planned and why they planned for other, you know, Hezbollah, Iran, other people joining in their fight, this memo was found in a Hamas tunnel by the IDF, so there's just vital intelligence that they found in the tunnels, which caused them to have to go in some tunnels, there's still an inversion, like why go in a tunnel if you don't have to, some of them, you know, the explosives and the booby traps, but again, a way to mitigate that and to use the robotics and the dogs and everything, one of the methods you've seen on TV is the legacy explosives, so basically, stringing explosive all throughout the tunnel, if you have a mile-long tunnel, that's a lot of explosive as much as it is if you do the liquid explosive, but you could even, you know, use an anti-tank mines or whatever, just every few feet, your daisy chaining explosive, all the length of a tunnel, and that's that exploding the tunnel, right, so explosive force, but this is a very, throughout the war, the idea found even when they exploded the tunnel, if they left or even a certain amount of time had passed, some of those tunnels, Hamas would just invest the time to dig them back out because it's still earth, one of the most effective ways, which I mentioned was done in 2019 in Lebanon, is wet cement, so you're filling the void of the tunnel, which hundreds of miles, don't forget, with something harder than the dirt that they would have to dig it out if you just, depending on, you know, the structure, of course, you have the rubble, which is hard to deal with, and if you have the rebar reinforced concrete, you explode that, it's still an effective way, but the most effective way is wet cement, but then there's a cost of it, right, so you're talking hundreds of trucks of wet cement, that there's a transportation weight in all of this, and I think the estimate is 1,000 tons to fill a one kilometer tunnel, I think it was, and it's around 2.5 million dollars, so you get, you basically have a resource cost implication of destroying the tunnel, at least prefer you're not going to use wet cement for 600 miles, just not enough, you can dig it out, if you're rebuilding, you can use explosive force, it's a big deal, and then the IDF, of course, have developed new creative ways on creating a cheaper cement that is harder, you know, PSI, what they say, I'm not a geologist, my friend, a sapper geologist is, he'll find this interesting about using wet cement mixtures of it, you know, making it harder than dirt, but not as hard as, you know, straight cement, you know, mixing the properties of it, so, you know, that's a pretty much, hopefully, there are a lot of lessons there, so what's the percentage of found I get? A lot, what's the percentage of destroyed? A lot, is there an area in Gaza that you can say there is no tunnels, there are a few, where the IDF have been working for two years in the buffer zone, like I said, along the border with Egypt and Rafa, of course, you have areas like along the sea, why the Al Mawasi humanitarian zone, because there was no tunnels there, because the water table is too high, there are some, but there is, even within this, as we're talking, the 53% that the, is on the yellow line, which the IDF will control, there are still thousands of tunnel shafts, hundreds and hundreds of tunnels, where it really becomes important, like I said, for the stabilization force is that that will be a giant mission, as much as demining will be, how do you demilitarize an area to create, to start building, right, you, there are engineering capabilities that you really have to think through, that it's a massive problem to be sure that you have mapped the tunnel network underneath you, that you're not sitting on top of the tunnel, which happened to the IDF multiple times, but also then you once you found it to destroy it, ultimately, all of these evolutions are important for all militaries of the world, because tunnels aren't going anywhere, like we said, they're popping up all and becoming a factor in multiple areas, it's also makes sense to go underground, so what are the, the tasks that you might have to do if you know they're there, whether the capabilities, what are the lessons of this war that could be applicable to include that paradigm shift of they aren't always obstacles that you have to deal with, they can also be maneuver corridors, advantages in God forbid, which I've written a lot about, you're defending, knowing what's underneath you is really important so that you can maximize the defensive properties that are there, so many lessons from the Gaza tunnels that apply to the future of warfare, but also apply to the future of Gaza and the stability of this, what they call the Gaza Metro, which is still there and has to be dealt with at a very high priority, well thank you for listening, I hope you enjoyed the show. Thanks for listening to the Urban Warfare Project podcast, the podcast is produced by the Modern Wars 2 at West Point, what you hear in each episode are the views that are participants and do not represent the positions of West Point, the Army, or the U.S. Government, you can subscribe to the Urban Warfare Project podcast on Apple Podcasts, Stitcher, or your favorite podcast app, and be sure to check out NGY's other podcasts, as well as the new articles we're publishing every day on our website, thanks again for listening.