The Beginning of Tunnel Usage in Ancient Times
We all know that a war can be fought in 5 different domains such as land, water, air, space, and nowadays, cyber. Fortunately or unfortunately, depending from which side you are fighting from, there is another front: subterranean tunnels. We can find references to one of the first tunnels made by mankind dating back to 2200 B.C., the first tunnels used for combat by the Assyrians in the 9th century B.C., and the first tunnels used for guerrilla-like warfare by the Romans before 135 A.D.. In practice it sounds fairly easy to mine underground enemy walls or fortifications in order to attack them when they least expect it. Sadly, as history has shown, it actually isn’t. Many of those trials of attack were countered by lighting different materials on fire to create a smoke that asphyxiates the intruders or by creating a countermine to catch the enemy of guard even more.
The US and its Fight Against Tunnels in the 20th Century A.D.
In the 2nd World War, the US considered massive bombardments from the air and naval forces to be enough to stop the Japanese forces to continue on in the war. They were wrong. Unknowingly, the 32nd Japanese Army prepared the most complex system of tunnels and caves known in warfare history. The underground systems were used as Control Rooms, weapon depots, hospitals, and even as the location of a palace. Those systems were so well thought out that on every beach the Americans wished to land troops on, there would be a Japanese fortification.
One of the most famous battles, in which the Japanese have deceived the Americans, was the battle of Peleliu. Peleliu is a small island in the Pacific Ocean which measures 13 square km and was under the occupation of the Japanese Empire. In 1944 American Intelligence taught that the Japanese had around 1000 troops on the island, due to its small size. However, the Japanese had finished their tunnel structures months before the attack and housed 11000 soldiers in them. As a result, the US Pacific Fleet had severely underestimated the Japanese resistance, which caught them off guard. The operation was originally supposed to last for only 3 to 5 days, but it ended after 72. Furthermore, this failure in intelligence would go on to cost the Americans a third of the original manpower deployed on Peleliu. What number of people did Japan lose during this fight? Incredibly, it’s actually easier to say how many of them survived as about 35 soldiers continued on living in the caves on the island for over 18 months after the American attack, after which, once they were discovered they surrendered. Indeed, the Americans won this fight, but at what cost? Did you ever think why the US resulted to using the nuclear bombs? The answer to this is simple: the devotion of the Japanese to fight until the very end of their lives with the sole purpose of killing as many US troops as possible had scared the Americans, and understandably so. Besides this reason, the American specialists came to the conclusion that if they were to invade Japan, the operation will last for 2 more years, and it would cost them at least 863,000 casualties and 267,000 more lives.
When the Vietnam War took place, the Americans had to reface the challenge of tunnel warfare, but under a different form. Due to the nature of the War in Vietnam, a stronger emphasis on the guerrilla warfare was made by the Vietcong and North Vietnam troops. The armies under Ho Chi Minh used the tunnel tactics to fight the French one decade before the Americans arrived. They managed to perfect the military strategies of the subterranean domain. In comparison to the Japanese, who were using the tunnels to go behind the American lines, the Vietnamese were using those systems to sneak into the US bases. This strategy let them plant mines and bombs within those camps, resulting in the sabotage of the American War effort. Instead of using explosives and chemicals to rat the Vietnamese armed forces out, US soldiers used volunteering men in a direct underground infiltration tactic. Those soldiers received the Tunnel Rats title. The strategy has proved to be effective and it also boosted the morale of the troops. The Tunnel Rats were treated as being the best out of the best in the eyes of their brothers in arms. Even so, throughout time the Vietnamese Armies learned how to counterattack those tactics with more interesting strategies. They were flooding the systems and setting up a number of different traps in the tunnels and mines. Some of the more interesting ones were the booby-traps which included trip wires or animal traps. Leaving the connotations of the name aside, a booby-trap is set-up with the intent to harm or kill its unsuspecting victim. When an American soldier would touch the trip wire traps they would be buried alive in the tunnels, or if they touched the leaves placed above their heads they would be attacked from above by venomous snakes. There was also the threat of other Vietnamese combatants. Fire fights were very common in the dark tunnels, and their imminent presence terrified the Tunnel Rats. One Tunnel Rat recalls that he reached a stage in which he could literally “smell where there was another human being’s presence”. The conclusion of this fight against tunnels? The US’s Tunnel Rats lost 36 lives and had around 200 wounded soldiers out of 700. This was one of the highest casualty rates in the Vietnam War.
What About The Present?
The United States of America is now facing another war, and this time on its own territory. The War on Drugs has been going on for more than 50 years now. Drug abuse was named the “public enemy number one” by the president Nixon in a message sent to the Congress on Drug Abuse Prevention and Control. In 2010, the US Customs and Border Protection authorities discovered the "longest ever" tunnel spanning the US-Mexico border. The tunnel measures 790m and it stretches from a warehouse near the Tijuana airport to another in the Otay Mesa community in San Diego, California. This is not the only cross-border tunnel found by the US authorities. In fact, another one was found during the same month and following the same route.
The search for such illicit tunnels began back in 1990, and today a total of 183 have been unveiled. Last year, another tunnel going by a similar route from Tijuana to San Diego was found by the San Diego Tunnel Task Force. This one was smaller, measuring at 610m. Even so, the tunnel turned out to be equipped with railways, plumbing and ventilation systems. The Task Force seized over 590kg of cocaine, 39kg of methamphetamine, 7.7kg of heroin, 1,360 kg of marijuana, and 0.9 kg of fentanyl from the tunnel.
Well, the future does seem a bit brighter. The US Army, Marines, SOCOM (Special Operations Command), and Pentagon are working now more than ever on training their forces for underground warfare. The American Army and Marine Corps are turning their views to the new/old subterranean domain while the Pentagon is preparing those tunnels for instructing US troops about Guerrilla warfare and disaster response. The Pentagon even issued access to different tunnel systems under US urban centers and colleges from the DARPA (Defense Advanced Research Projects Agency).
But why put in all of these efforts if it’s only about the War on Drugs? Because it isn’t. A tunnel made by the Iranian Soldiers in Eastern Syria big enough to store and hide sophisticated weapon systems was recently uncovered. In October 2019, ISIS leader Bakr al-Baghdadi retreated into a tunnel once he was closed in by a US Assault Team. And finally, let us not forget about the tunnels built in North Korea. There are over 5,000 tunnels underneath North Korea going through “mountains and hillsides to house artillery, ammunition and medical supplies,” VOA reports. At least one of those tunnels is known to have one of its thirds on the South Korean side of the border. As you can see, the US has learned from its past fights and wars against tunnels while trying to think ahead with better prepared troops and improved intelligence in the subterranean domain.