I had had a sharp reminder of how inter-Party jealousies had the potential to cripple the best laid plans. I had seen how difficult, if not impossible, it was to mount a quick operation. I had received the warning of an impending attack several weeks in advance, but the lack of communications, the lack of any sort of mobile reserve force which could be despatched to a critical point, and the lack of a willingness among Leaders and Commanders to cooperate, had negated this advantage. Our efforts were belated, and therefore only partially succeeded.

On the other hand I had been shown how hard it is for aircraft to kill guerrillas in the mountains, and I knew for certain that the jugular vein of the Soviets in Afghanistan was the Salang Highway.

The Salang Highway had been constructed by the Soviets in the sixties as part of their development aid. Its primary purpose was to link Kabul to the Soviet Union and to establish a permanent, all-weather route over the Hindu Kush so that there could be a free flow of goods and people in both directions. Certainly its military significance had been appreciated, if not openly discussed. It effectively joined northern to southern Afghanistan, something that had not been achieved before, cutting the journey time from weeks to hours. While the Soviets had concentrated on this strategic link, the Americans struggled to build the ‘ring road’ to the south of the inhospitable mass of mountains, the Hazarajat, that sat in the centre of the country.

If the base area around Termez was the heart, which pumped supplies along the Salang artery to the head of the war effort at Kabul, then the choke point at the neck, 120 kilometres from Kabul, was the Salang Tunnel. Also built by the Soviets in 1964, the tunnel is a masterful piece of engineering. Located just east of Mount Salang, at 11,000 feet up, it is the highest tunnel in the world. It was blasted through solid rock for nearly five kilometres at the point where the Hindu Kush is at its narrowest. It is expected to remain open throughout the winter but this is only possible with the extensive use of bulldozers clearing snowdrifts and rock falls on the approaches. Although lit inside with power from its own generators, the journey through was seldom pleasant. In winter Soviet soldiers recall the intense cold, trucks slipping on ice, filth, the stink of fumes and the claustrophobic feeling as they disappeared into the mountain. The horror of being entombed remained with many until, after some 15 minutes if all went smoothly, the fresh air and freedom at the far end was reached.

Entrapment was not an unreasonable fear. In 1982 a series of landslides of snow and boulders blocked the road, bottling up a large convoy inside. The dense clouds of exhaust fumes quickly built up a poisonous concentration of carbon monoxide in the confined space, causing several Soviet deaths, much sickness and total chaos. This incident was erroneously reported as being a Mujahideen ambush and the number of deaths was exaggerated. It resulted in more ventilation shafts being bored through the roof. Stringent security was enforced at the tunnel. At each end permanent company posts were built to guard the entrances from close attack. Check points and barriers were in operation, with security troops or KHAD officials scrutinizing documents and searching suspect vehicles.

To me it was probably the most alluring target in Afghanistan. It cried out for attack. To destroy the tunnel would cause staggering logistic difficulties for the Soviets and be a Mujahideen triumph of the first magnitude. But, as I was to appreciate more and more, selecting a target was easy, hitting it was the problem.

Nevertheless, I determined to try. First there were the technical calculations of the quantity, type and positioning of the explosive. On the advice of a CIA expert it was established that several tons were necessary, which meant using a truck. Then, I was told one truckload would only cause damage that could be cleared in two or three days, so three trucks positioned at intervals inside would be needed.

There was a complication with the type of truck. Vehicles were liable to search on entering, so packing explosives into an ordinary lorry was impossible. We opted for a fuel tanker. With modification these vehicles could be filled with explosives, while a cursory inspection would still reveal fuel. Afghan government tankers would be ideal, so one was purchased for examination and testing. Another difficulty arose. A full tanker must enter the tunnel from the north end as only empty ones came up from Kabul in the south. The trouble was that the only road from Pakistan into Afghanistan ended up m Kabul. How to get three tankers packed with explosives positioned north of the tunnel was probably the most baffling of our tasks. They would have to travel up empty, and somehow the explosives would be carried m on horses or mules to a suitable rendezvous for loading.

We had to find several volunteer drivers to be trained and briefed. This proved difficult. It involved high personal risk and was not the sort of operation popular with the Mujahideen, who preferred the glamour and glory of the battlefield to clandestine sabotage activities. In practical terms the vehicles would need to be driven into the tunnel, have some sort of mechanical breakdown at the appropriate positions, the timing devices started, and then the drivers must get out. Motor cycles, or another vehicle leading the way, were possibilities, but a lot could go wrong. Breakdowns always caused chaos inside, plus an immediate reaction from the security units at either end. The tankers would need to be disabled in such a way that they could not be quickly towed clear. Both a remote-control exploder and a timing device were to be used. A timing mechanism was important in case the remote control one did not work. If all went well, the remote control would be used as soon as the drivers got out, in the hope of catching the Soviets inside attempting to clear the breakdowns. This they would try to do at once, with their suspicions aroused by three tankers stalled simultaneously. The timers would be set for about half an hour, long enough for the drivers to escape, but not long enough for the vehicles to be recovered, or the explosives found and defused. To obtain the maximum effect the operation was scheduled for the winter when Kabul would be short of supplies and clearance hampered by the weather, with bulldozers battling ten-foot snowdrifts on both approaches.

It would have been a magnificent Mujahideen triumph, but sadly it was not to be. Several times Commanders agreed they would do it, but always after a few months I would get word that it was impossible to find the men. Perhaps it was too ambitious, although I personally do not think so. It had all the makings of a classic guerrilla attack. History would surely have recorded it as the supreme example of a single act of sabotage crippling a modern army for weeks.

The Salang Highway was the most closely guarded road in Afghanistan. From the newly built bridge at Hairatan, just west of Termez, to Kabul troops were deployed at scores of posts, large and small, each sited for mutual support. At intervals of about 20 kilometres large garrisons would be positioned with a mobile reserve force, artillery, armouredvehicles, tanks, and often Air Force ground controllers. They seemed not so very different from the fire support bases that the Americans built all over South Vietnam to protect supply routes, or support search-and-destroy missions. At places where the ground favoured an ambush the smaller posts would usually be sited on high ground overlooking the highway. Each post would be surrounded by wire and minefields, and was linked to its sector headquarters by radio. Mines were frequently strewn off the road at potential ambush sites, while any trees or scrub that might provide cover were cut down.