Land mines are explosive devices buried in or placed on the ground, designed to detonate when a person, vehicle, or animal triggers them. They are among the most persistent weapons ever created, with some mines laid during World War II still capable of detonating more than 80 years later. An estimated tens of millions remain scattered across dozens of countries, continuing to kill and injure thousands of civilians each year, long after the conflicts that placed them have ended.
Anti-Personnel vs. Anti-Tank Mines
Land mines fall into two broad categories based on their intended target. Anti-personnel mines are designed to injure or kill people on foot. They’re small, often no bigger than a hockey puck or a soda can, and contain relatively little explosive. One widely used model holds just 6 ounces of TNT. They typically detonate under 7 to 12 kilograms of force, roughly the weight of a stepping child.
Anti-tank mines are built to disable or destroy vehicles. They carry 12 to 30 pounds of high explosive and require 300 to 400 pounds of pressure to trigger, which means a person walking over one usually won’t set it off. That said, some anti-tank mines can be modified to detonate under lighter pressure, and the blast from one is powerful enough to destroy an armored vehicle or kill anyone nearby.
How They Detonate
Most people picture a mine as something you step on, and for the majority of mines worldwide, that’s accurate. Pressure-activated fuzes are the most common trigger. But several other mechanisms exist, and understanding them helps explain why mine clearance is so dangerous.
Tripwires are thin wires strung across a path and connected to a mine’s fuze. When someone snags the wire, the mine detonates. These are typically paired with fragmentation mines, which spray metal shrapnel over a wide area. Tripwire fuzes are designed to require several kilograms of force so that falling branches or small animals don’t set them off. Over time, the wire rusts and eventually breaks, which can neutralize the mine, though some models have a backup pressure fuze.
Less common triggers include electrical command wires (allowing a soldier to detonate the mine remotely), magnetic influence fuzes that detect the metal in a passing vehicle, and tilt-rod fuzes, which are thin rods protruding from the mine that activate when something pushes them sideways.
Three Types of Anti-Personnel Mines
Anti-personnel mines come in three main designs, each causing a different pattern of injury.
- Blast mines are the simplest. They sit just below the surface and send an explosive force straight upward when stepped on. The blast typically injures one or two people, often destroying a foot or lower leg.
- Bounding fragmentation mines are far deadlier. When triggered, they launch an explosive canister about 1.5 meters (roughly waist height) into the air before detonating. The explosion sprays shrapnel in all directions with a casualty radius of 30 meters (about 100 feet).
- Directed fragmentation mines sit on the surface and fire shrapnel outward in a 60-degree arc, like a deadly shotgun blast. Their casualty radius can reach 100 meters (over 300 feet), making them the most lethal anti-personnel mine by area covered.
The difference in lethality is dramatic. A blast mine injures the person who steps on it. A bounding or directed fragmentation mine can kill or seriously wound everyone within a large radius. When a fragmentation mine detonates, anyone within about 10 meters is likely to die, and injuries extend much farther.
The Butterfly Mine
One of the most notorious mine designs is the PFM-1, often called the “butterfly mine” or “Green Parrot” in Afghanistan. It looks nothing like what most people imagine when they think of a mine. It’s a small, flat plastic device with two wings (one thicker than the other), colored green, khaki, or sand-brown. The thicker wing contains about 37 grams of liquid explosive.
Butterfly mines are scattered from the air, sometimes by the thousands, over a wide area. Their plastic bodies make them nearly invisible to metal detectors, and their shape has been widely reported to attract children who mistake them for toys. The PFM-1 uses a hydraulic pressure fuze with a built-in arming delay, so it doesn’t detonate immediately after landing. A self-destruct variant, the PFM-1S, is supposed to deactivate after about 40 hours, but testing has shown these mines remain functional far longer than intended.
How Long Mines Stay Dangerous
One of the most troubling things about land mines is their longevity. Most of the mines threatening civilian populations today were manufactured more than 50 years ago, and many have been buried for 30 years or longer. Their lifespan depends heavily on the environment they’re sitting in.
Water is the primary cause of deterioration. Mines buried in wet, acidic, clay-heavy soils corrode and break down significantly faster than those in dry climates. In Cambodia, where soil is highly organic and rainfall is heavy, researchers found that a substantial proportion of examined mines were no longer capable of functioning. The rubber seals, wooden components, and mild steel casings had degraded badly.
By contrast, metal-cased mines recovered in Jordan’s dry climate were remarkably well preserved. Some World War II-era mines were still functional decades later. Mines examined in Afghanistan fell somewhere in between, with wetter areas showing faster deterioration. Fire damage and weathering of plastic casings also play a role, because once the outer shell is breached, water and soil chemistry attack the internal components much faster.
The takeaway is that while mines do degrade over time, you cannot count on it. A mine in dry desert sand may remain lethal for generations. Even in harsh environments, the rate of failure varies so much that clearance remains the only reliable solution.
International Law and the Mine Ban Treaty
The 1997 Ottawa Treaty, formally called the Anti-Personnel Mine Ban Convention, prohibits the use, stockpiling, production, and transfer of anti-personnel mines. To date, 161 countries have formally agreed to be bound by the treaty.
The treaty’s major gap is who hasn’t signed. The United States, Russia, China, India, Pakistan, Israel, Egypt, Saudi Arabia, Iran, North Korea, South Korea, and Myanmar are among 31 nations that remain outside the convention. Several of these countries are among the world’s largest military powers, and some have actively used mines in recent conflicts. The absence of these states means that while the treaty has significantly reduced global mine use and stockpiles, it hasn’t eliminated the problem.
Why Mines Are So Hard to Remove
Land mines were designed to be cheap and easy to lay but expensive and dangerous to remove. A single mine can cost as little as a few dollars to manufacture, while clearing it can cost hundreds or even thousands of dollars. Mines are often laid without maps or records, meaning no one knows exactly where they are. Flooding, erosion, and shifting soil can move mines far from where they were originally placed.
Plastic-bodied mines like the PFM-1 are especially difficult because they contain almost no metal, making standard metal detectors unreliable. Tripwire-activated mines add another layer of danger for clearance teams, since the wires are nearly invisible and may be hidden in vegetation. Fragmentation mines connected to tripwires are disproportionately significant for clearance operations because even triggering one at a distance can send lethal shrapnel across a 30-meter radius.
The earliest recorded use of persistent, victim-activated land mines dates to the American Civil War, but widespread deployment didn’t begin until the 20th century. In the decades since, the sheer volume of mines laid across conflicts in Southeast Asia, Africa, the Middle East, and Eastern Europe has created a global clearance challenge that will take generations to resolve.