While in Viet Nam earlier this month, we visited the tunnels at Củ Chi just outside of Ho Chi Minh City (formerly Saigon). I crawled through a 15 metre section of the tunnel, which has been enlarged to accommodate the bulky frames of westerners, yet despite this short distance, I could not wait to find the exit. On the way to the exit we passed the 'entrance' (ie a small hole) to another tunnel which would take you to the Saigon river. For several nights afterwards, I woke with imaginings of being lost within the vast 250 kilometre network and what it must have been like for the Viet Cong who fought a war in conditions significantly worse than the tourist-enhanced section of the tunnel I experienced.
Imagine fighting a war underground in the suffocating, sweltering blackness of tunnels, barely tall enough for a man to crawl, let alone walk, and where a wrong turn could send you plunging onto the lethal bamboo spikes of a punji stake trap. Elsewhere carefully placed trip wires were primed to detonate a grenade or release a box of scorpions onto their unsuspecting victim. In other places, the entire walls of the tunnel were covered with an impenetrable mass of spiders and stinging fire ants. Air, food and water were scarce and the tunnels were infested with ants, poisonous centipedes and snakes, and mosquitoes.
The Viet Cong would spend most of the day in the tunnels working or resting and come out at night to scavenge for supplies, tend their crops or engage the enemy in battle. During periods of heavy bombing or American troop movement, they would be forced to remain underground for many days at a time. Sickness was rampant. Malaria accounted for the second largest cause of death after battle wounds, and all who lived within the tunnel network had intestinal parasites of significance.
American officials recognized the advantages the Viet Cong held with the tunnels, and launched several major campaigns to search out and destroy the tunnel system, but these were, for the most part, unsuccessful. When troops did find a tunnel, they would often underestimate its size. The two main responses in dealing with a tunnel opening were to flush the entrance with gas or water to force the guerrillas into the open, or to toss a few grenades down the hole and "crimp" off the opening, however the clever design of the tunnels, along with the strategic use of trap doors and air filtration systems, rendered these strategies ineffective.
To penetrate this underground world, and overcome a determined but poorly equipped peasant army, the American military had to revert to the most basic form of combat - hand to hand. Tunnel rats - an elite band of volunteer soldiers selected for their bravery and small stature, were stripped to the waist and armed with just a torch and a pistol to spend hours inching through the humid, dark tunnels in a deadly game of hide and seek. The rats would search for anything suspicious that would trigger a carefully primed booby trap. Some died in the process, and many more were dragged screaming from the inky blackness.
The tunnel system played a huge role in protracting the war and resisting the allied forces, eventually culminating in their withdrawal. You cannot be anything but awe-struck by the grit and determination of those who built and fought in the tunnels in what was truly a David and Goliath battle. War is Hell at the best of times and indescribable at worst.