Last month, I read my way through the fascinating The Tunnels of Cu Chi, written by Tom Mangold and John Penycate. The book tells the story of the tunnels dug by the resistance fighters in South Vietnam as a way of neutralising the technological superiority of first the French military and then the US military in their wars for national independence and national reunification.
The tunnels first developed as a means of communication and transport between the basements built by villagers, and which they used to protect themselves from the effects of aerial bombardment and reconnaissance-in-force by military personnel. The Viet Cong, which drew its personnel largely from the population of the villages, quickly appreciated their military value, and set about employing the peasants to expand the network of tunnels and build sizeable chambers within them. By the early 1960s, the network of tunnels covered a massive area only 20 miles north of Saigon, a region labelled to the US military as the ‘Iron Triangle’, and included chambers for hosting large groups of personnel, factories for producing light armaments, and hospital wards.
The tunnel network bedevilled the US army and marine personnel charged with clearing the area of Viet Cong forces. The tunnels gave the Viet Cong personnel a means by which they could launch lightning attacks and ambushes on US and Australian soldiers, equipment and even military bases, and then disappear without trace via hidden entrances to their tunnels.
To counter the Viet Cong tactics, the US soldiers developed methods for locating tunnel entrances, and then dealing with the threats that they posed. One such method was to send soldiers down the tunnels after the Viet Cong, to fight and kill their opponents, gather intelligence, and destroy the tunnels. Over time, the US soldiers managed to hone their skills so that they were able to deal effectively with the threats – such as booby traps and enemy soldiers – that they found in the tunnels, while also gathering important intelligence. But they couldn’t find a way to destroy the tunnel network. The strength of the soil in which the tunnels were dug, and the sheer extent of the tunnel network, meant that dynamiting ‘cleared’ tunnels did little damage to them.
The Americans resorted to clearing whole areas of contested land to create ‘free strike’ zones. They moved villagers out of the area and razed their villages, and then cleared the land of vegetation, defoliating forests and jungle and pulling down trees. But the extent of the underground network meant that the Viet Cong forces could survive underground during the day, coming out at night for fresh air, and retain their freedom of movement in the area.
As a result, the US army never won the quick victory that its technological and material superiority should have allowed it to win over the poorly-equipped villagers. Instead, it took long years of attrition to wear down the Viet Cong, through their loss of manpower and loss of morale resulting from their having to live in the unhygienic and fetid tunnels.
The Tet Offensive of January 1968 saw the end of the Viet Cong as an effective fighting force. Finally thrown into an open battle against the US and ARVN forces, they were decimated in firefights at which the Americans excelled, and which allowed the Americans to use the full range of their capabilities. After the Tet Offensive, the US had won the land war.
However, in a supreme irony, the moment of greatest US triumph was also the moment at which the US populace lost the heart for the fight. Having been told by their Generals and administration that they were winning the war – which was undoubtedly true, as the US slowly ground the fight out of the Viet Cong – the Tet Offensive came as a shock to the population. An enemy which was supposed to have been beaten had launched a daring and spectacular attack. No matter that that attack had led to its destruction, the US population drew the conclusion that the war was hopeless and not achieving its objectives, and support for it began to drop. And neither the administration nor its Generals were able to convince the population otherwise.
The tunnels of Cu Chi, then, had succeeded in their purpose. They had enabled the Viet Cong fighters to fight for sufficiently long as to break the will-to-fight of their opponents.
There is therefore a great irony in the fact that, nine months after Tet, the US military, apparently quite by accident, found a means by which to destroy the tunnels. From the book:
On 31 October 1968, President Johnson had ordered an end to the bombing of North Vietnam as a gesture to hasten the convening of peace talks in Paris. Strategic Boeing B-52s, adapted to carry over a hundred “iron” bombs each, had long been flying missions form their bases at Andersen Air force base on Guam and U-Tapao, Thailand. These huge, high-flying aircraft never saw their targets; they were guided in and their bombing was directed by ground radar up to two hundred miles away. They were not allowed to bomb within a three kilometre radius of error next to friendly forces. After the bombing halt in the North, they were more available to ground commanders in South Vietnam. The generals decided to use the bombers to saturate the free strike zones with 750- and 500-pound high-explosive bombs.
The bombs were dropped in sticks that left a mile-long swath of total devastation. The landscape erupted with a string of explosions. Tons of earth – along with trees, buildings, and human bodies – cascaded into the air. A B-52 strike could be seen, heard and felt for twenty miles: a thunderous symphony of destruction that shook the face of the earth and left it permanently scarred. In Cu Chi and the Iron Triangle there was, by 1969, little vegetation left and few people; only a handful of guerrillas hung on in conditions of extreme privation in the tunnels. For them, the most destructive of the B-52s’ bombs were those fused to explode, not in the air on impact, but after they had penetrated several feet into the ground. The explosion from one of these created a local earthquake that collapsed the sturdiest of tunnel walls. The resulting craters, which still deface the landscape, were up to thirty feet deep – huge pits that sliced into the tunnel system, making it unusable and irreparable. “A five-meter hole could be sufficient to to destroy a tunnel,” said Major Nguyen Quot. “B-52 bombs made holes twelve meters deep.” Air holes were blocked by debris. When the tunnel system was blocked in several places, air could no longer circulate and the inmates suffocated. Carpet bombing by B-52s gradually succeeded where the CS gas and demolitions charges of the tunnel rats had failed – denying the use of the tunnels to the Viet Cong.
But this military success came too late to affect the outcome of the conflict. The long, indecisive war of attrition, the shock of Tet 1968, and the war’s deep unpopularity at home had already undone America’s resolve in Vietnam.
This technology – the B-52 with late-fused bombs sufficiently powerful to create huge pits in the ground – existed when the US campaign began in 1964. The US army and marines became aware of the tunnels in their very first encounters with the Viet Cong in that same year.
For whatever reason, the appropriate technological solution was never applied to the otherwise-intractable problem.
Did the US field commanders never think of applying the solution – either because they weren’t aware of it, or because they were aware of it but couldn’t make the connection?
Or did someone make the connection, but failed in their attempt to sway those further up in the hierarchy of the value of diverting B-52s away from missions against Hanoi to missions against the Viet Cong?
The failure raises all sorts of questions about the value of strategic bombing as against tactical bombing. And that’s without raising the question of the morality of targeting civilians, especially when targetting military formations might shorten a war.
Regardless. The Americans failed to employ a technological solution, which they had at hand, in a timely manner to the key obstacle to their success. And as a result, they lost a war.
Imagine how different the world might be today, if the decision-makers in Washington had made the simple realisation that the key to a quick and overwhelming victory was to destroy the Viet Cong’s tunnels using B-52s.
* * * * *
Heuer devotes chapter 6 of Psychology of Intelligence Analysis to the topic of keeping an open mind when generating understandings of and solutions to problems. He suggests various ‘mental tools’ for doing this effectively – such as questioning assumptions, and seeing different perspectives – and knowing how to recognise when it is time to change one’s mind, and how to stimulate creative thinking.
The exercise on page 68 of the book serves to emphasise the importance of unconscious assumptions in preventing us from reaching effective solutions efficiently. Bringing those assumptions to our consciousness requires meditative, reflective thought, and discussions with others.
‘Thinking outside the box’ means thinking outside the barriers and restrictions which our minds have automatically and unconsciously erected around our thought processes. In the context of Cu Chi and the Iron Triangle, the solution to the problem of the underground tunnels was not in the immediate vicinity of the tunnels: it was thousands of miles away, at Andersen Air Force Base in Guam and at U-Tapao, and it would be applied from 40,000 feet in the air.
UPDATE [September 22, 2014]: Craig Pirrong over at Streetwise Professor has written a post discussing the adverse consequences of President Johnson’s diversion of the US bombing campaign in North Vietnam away from military targets towards targets with political value.