WASHINGTON, Nov. 16 (UPI) -- If Taliban and al Qaida forces abandon Kandahar to wage a guerrilla war from the hills outside the city, they will find little security in the famous cave and tunnel network that crisscrosses the southern part of Afghanistan.
Recent journal reports from Fort Leonard Wood and Fort Leavenworth provide a wealth of information on the difficulties the Soviets encountered dealing with the Afghan mujahedin operating inside these centuries-old tunnels, but more importantly, they also discuss tactics and procedures the Russians developed to efficiently contend with them.
Afghanistan has repeatedly been invaded from one direction or another, and the locals take shelter in the tunnels until the battles raging on above their heads move on to another valley or pass. During the Soviet invasion in the 1980s, the people and mujahedin guerrillas alike found the tunnels to be particularly secure locations to hide from Soviet airstrikes and artillery barrages.
The mujahedin quickly learned to carve caves into the sides of the shafts, where they could hide themselves, weapons and other supplies. They also used the tunnels to move for literally miles underground to surface at ambush sites and attack positions, then disappear as quickly as they had come upon unsuspecting Soviet forces.
But as the Soviet-Afghan war progressed, the Russian and Afghan communist forces developed approaches to contend with these ambushes and soon began taking the war directly to the underground mujahedin. By the mid-1980s, they had developed effective tactics to minimize their own casualties and clear tunnel complexes of guerrillas and insurgents.
The Soviets learned to form multiple covering groups and hold the openings to all access shafts in a given area, since in most cases the tunnels the shafts led to were interconnected. Since they knew civilians often hid in the tunnels, the first step was to warn anyone inside that the tunnels were about to be blown up, and give non-combatants an opportunity to flee.
Nevertheless, the Soviets quickly learned the importance of yelling demands to come out without exposing themselves to answering gunfire.
If nobody answered or surrendered, the Soviets would generally toss a number of concussion grenades into the mouth of the shaft to demonstrate their intent to proceed. After they detonated, they would once more demand that anyone hiding deeper in the tunnels surrender.
The Soviets would next lower grenades on cords at varying depths and detonate them, to kill any guerrillas hiding in side niches along the walls of main access shaft, which was generally vertical. Only after this would they lower 10 to 15 pounds of explosives to the bottom of the shaft. This charge was connected to a second smaller charge of approximately 2 pounds of explosives that was placed just inside the mouth of the entrance and set to initiate a fraction of a second before the main charge at the bottom of the shaft.
The result was what the Soviets called the "stereophonic effect." The explosion of the top charge would tightly plug the upper sections of the shaft with gases. When the shock wave from the second charge struck the shock wave from the first, it would rebound off the higher gas mass above it and ricochet back down the throat of the shaft deep into the tunnels with devastating effect.
The Soviets also learned they could link the blast effects in tunnels with multiple entries by rigging charges as just described in all identified openings and setting them off simultaneously. They called this massed detonation the "quadrophonic effect" and learned to stay far back from the entrances of any tunnels when the blasts were initiated because rocks and debris would fly from the openings like a volcano.
After setting off the main blasts, the Soviets would drop smoke grenades into the shafts. If the smoke disappeared, it meant that some of the tunnels still were intact and ventilating, which required that special teams enter and hunt down potential survivors.
Generally, anyone still alive was completely dazed, and the Soviets learned to confuse them further by setting off whistling pyrotechnics that resembled Roman candles. For some reason the showering mass of stars would blind and dazzle the mujahedin, perhaps because they had been underground for so long their eyes were not used to the bright lights. Specially trained commandos equipped with flashlights and armed with knives, entrenching tools, pistols and grenades would then make short work of any mujahedin still hiding inside.
The Soviets also made use of flamethrowers, though they found that unless they rigged the triggering mechanism of the weapon with a cord and lowered it into the tunnel, the gunner would generally get shot by a mujahedin hiding within the entrance shaft as he leaned over to fire the device.
Discussions with an analyst at the Army's Fort Belvoir, who requested anonymity, suggest the U.S. Army is well aware of the Soviet tactics, and in addition, has researched additional means to neutralize tunnels.
One method involves the use of a mixture of carbon monoxide and acetylene, which can be pumped into the tunnels until they are completely filled. Because the gas is heavier than air it has a tendency to stay put in the tunnel and not escape out any other tunnel entrances further along in the underground network.
This fuel-air mixture then can be detonated with a grenade or some other explosive, and the resulting blast literally blows out the entire tunnel network, if sufficient gas has been pumped into the tunnels. The concussive force is enormous and past use of this tactic by the German army during World War II suggests nobody inside the tunnels can survive the blast effects as long as sufficient quantities of the gas have been pumped into the tunnel network.
While representing a grim approach to warfare, it also guarantees minimal casualties for American soldiers facing an enemy seemingly committed to fighting to the death, regardless of how they are engaged, the analyst said.
The tunnels in Afghanistan in use today stem from underground irrigation works, also known as the karez system, which have been in existence at least since the time of the Mongol invasion in 1221 A.D., when many locals survived the atrocities of Genghis Khan by hiding in the tunnels until the Mongol hordes had moved on. Some historians claim the system may pre-date the invasion of Alexander the Great in 328 BC.
Because many of the rivers in Afghanistan run low during the dry season, the local people learned to extend the growing season well into the dry months by digging a vast network of tunnels that extend for miles into the surrounding foothills and mountains, where they intersect the water table at higher altitudes, and carry the water to the fields surrounding the cities and towns.
Open-ditch irrigation is used in northern Afghanistan, because the water table is relatively shallow, but in the south, the rural inhabitants are forced to dig deep trenches, as much as 30 feet to 50 feet deep, and cover them with mounds to keep the water from evaporating.
The tunnels are dug by farmers. They require an enormous amount of effort to maintain because of silt that washes through them along with the water that comes from the highlands. Every year the farmers expend extraordinary efforts shoring up collapsing walls with ceramic tiles and hauling the dirt and silt to the surface in goatskin bags, but the efforts permit them to grow sufficient food to feed their families and towns for the coming year.
Any karez destroyed by American and coalition forces in the coming weeks and months likely will be quickly rebuilt by the patient farmers after the war moves on, as they have been rebuilt numerous times in the past.
(Malcolm Visser, a West Point graduate and former U.S. Army combat engineer, works for Radian Inc., a defense contractor, on countermine and de-mining issues, and is a freelance writer.)