Yet war is at best a gibbering beauty, and much more than the detail of the fighting and killing that day it was the overarching sense of change, even hope, that sticks foremost in my mind. That autumn of 2001 the Taliban were routed across the compass face of Afghanistan by columns of Afghan irregulars backed by airstrikes and a handful of US special forces. A deadly enemy and their implacable host, well proven to be the legitimate target of vengeful retribution, were driven from power, a move that had the overwhelming support of the Afghan civilian population.

Who could have predicted then that ten years later the war would still be going on, even as the West prepares to leave Afghanistan? What chance now that it will ever end?

It is not the ghosts of 2001, the missed opportunities or the dead soldiers of the subsequent decade that now most trouble Western policy-makers and commanders in Afghanistan. In the wake of Barack Obama's decision to draw down US troop numbers in Afghanistan and transfer responsibility for the country's security fully to Afghan forces by 2014, it is the shadows of a departing Russian general and a slain Afghan president that stir greatest unease.

Lieutenant General Boris V. Gromov was 45 when he hopped off his armoured personnel carrier on Friendship Bridge over the Amu Darya river separating Afghanistan from Uzbekistan. He was embraced by his teenage son Maksim, who gave him a bunch of red carnations; father and son walked the last hundred yards of the iron span arm-in-arm to Soviet territory. Gromov never looked back. It was 11.55am, February 15, 1989: nine years and 50 days after Soviet troops had invaded Afghanistan in support of a Marxist coup. Gromov, commander of the Soviet forces in Afghanistan, was the last Soviet soldier to leave the country. Little could he have known that more than 20 years on his arch-enemies in the Cold War would face the same anxieties in walking away from the conflict.

The Communist regime that Gromov had left in Afghanistan collapsed three years later after its funding lines were severed. Fighting broke out between rival mujahideen groups entering Kabul, igniting civil war. President Mohammad Najibullah was detained as he attempted to flee the country. The fate of Najibullah, once the Soviets' most dynamic ally in Afghanistan and heir to their hopes of continued influence, was to be tortured to death by his captors. He ended his life swinging from a Kabul traffic control post.

Civil war, humiliation, the fall of allies and rise of enemies: as the West looks back on its own decade of intervention in Afghanistan and contemplates its coming withdrawal from the country, the twin images of Gromov's departure and Najibullah's downfall dominate the pantheon of its fears. These two moments feed the popular legend that no foreign war in Afghanistan has ever been successful and that the country is "the graveyard of empires".