My fixer sat down next to me in the packed and dilapidated minibus, whispering a hurried reminder to keep my head down at the army checkpoints.
We were outside Peshawar in north-western Pakistan and were travelling into the tribal areas along the Afghan border, strictly off-limits to foreigners. With my beard and local clothes, I did not look out of place among the tribesmen crammed into the ancient vehicle, but our cover would be blown if an official should happen to speak to me - I knew only two phrases in the local language, neither of them very helpful when facing arrest. I pulled my hat low on my forehead and hunched my shoulders, and we set off amid shouts and slamming doors.
As news stories describe with depressing frequency, the tribal areas are violent and life there is harsh. An autonomous region largely outside the remit of Pakistani national law, it is ruled by Pashtun tribal leaders according to traditional codes. Although tribal law is sophisticated in some respects, it nonetheless remains unforgiving, even brutal, and in the end comes down to the law of the gun. This violent life dates back centuries, but has acquired a new sharpness in recent years: as the reputed hiding place of Osama Bin Laden, the Tribal Areas are a crucial battleground of the American war on terror.
I was setting out to visit a place that helps to keep this region dangerous: the famous gun town of Darra Adam Khel. For over a century, the craftsmen of Darra have produced a wide array of firearms by hand, churning out many thousands of high-quality replicas from Lee- Enfield rifles to AK-47s, all indistinguishable from the originals. Sold freely to all comers, this supply of weaponry - in an area outside government control - is a factor contributing hugely to instability in the surrounding region.
As we crossed the roadblocked border, the scenery grew mountainous and sharp ridges of khaki rock cut into the clear winter sky - a for bidding landscape that matched the tense atmosphere. Tribesmen sauntered by the roadside with AK-47s slung casually across their backs. Eventually, we were among scruffy, flat-roofed buildings and the minibus shuddered to a halt. Stepping out, I looked about at the simple main street of Darra, lined with modest shops without much to sell, and felt it to be a distinctly mas culine environment. For once the ubiquitous bright blue burqas of elsewhere in the frontier region were absent; in fact there were no women to be seen at all; the town had an abandoned feel. Gunshots rang out sporadically - buyers, I was told, testing the merchandise.
I was promptly taken indoors to meet the khasadar - a local militiaman - who would, for a fee of several thousand rupees, oversee my visit. After much tea and handshaking, he took me around the warrens of basic workshops in which the craftsmen make their weapons, working with the simplest of tools and much skill. One squatted on the floor and filed away at a piece of steel that would eventually become an automatic pistol, stopping periodically to check his work with a plastic ruler. Another sat among hundreds of brass cartridges, filling them with gunpowder and gently knocking in the bullets with a small hammer. A third craftsman, bespectacled and professorial, showed me his large electric drill, decades old, but the most advanced piece of machinery I saw all day. I was amazed at these men's ability to produce such modern arms with the most modest of tools.
It was a powerful arsenal. Spread among the tiny factories are numerous gun shops where racks and racks of weapons of all types can be bought, along with ammunition piled up in bright boxes, explosives and hand grenades. Walls are covered in AK-47s or Heckler & Koch sub-machine guns, shotguns and pistols. Anyone with a suitcase of cash could equip a small army, no questions asked.
Suddenly, I was hustled upstairs by the khasa dar and my fixer, both with a look of suppressed panic on their faces. Showing me into a shabby office, they politely asked me to wait for a while and firmly closed the door behind them. Gradually, I became aware that somebody - presumably a local tribal elder - had found out about my presence in his town and wasn't happy. For longer than an hour I sat there, trying to divine what was happening and sipping the tea that was being offered to me; my fixer scuttled about, looking anxious. He assured me all was well, but I presumed that some urgent negotiations were being conducted, and payment agreed upon. Finally, the khasadar returned, smiling but with a hurried air - things had been settled, but he was keen to bring my visit to a close.
Before it ended, I was taken outside the town and presented with some Darra merchandise to try out: I fired an AK-47 into a cliff-face, followed by a pump-action shotgun and a pistol, all locally made replicas of astonishing quality. As I loosed off the rounds, a group of Afghan refugee children danced around happily, snatching the hot spent cartridges from around my feet, enjoying the rare event of a foreign visitor in their adopted town. Their easy familiarity with the firearms was alarming, and they fought over them when I finished, keen to strike martial poses for the camera. They accompanied us on the short walk back into town, marching along like soldiers, bearing the weapons on their shoulders.
I was struck by two things in Darra. First, the great power of the Pashtun tribes and the impotence of the central government: its representative, the khasadar, was clearly subordinate to the tribal chiefs. Second, the incredible and disturbing quantity of firearms available for sale to the first buyer. While these issues remain unaddressed, there seems to be no hope of ending the long instability of the tribal areas, and little prospect that future generations of frontier children will grow up in a better environment.
Paddy Docherty's "The Khyber Pass: a History of Empire and Invasion" is published by Faber & Faber (£9.99 paperback)