I still keep the single sheet of paper - dull grey, stark black font, with the seal of the British embassy in Kabul, dated 19 January 1989.

"I must advise you," it warns, "you should leave Afghanistan without delay while normal flights are still available".

The British ambassador then pulled down the Union flag and locked the gates of a magnificent compound Lord Curzon once said was worth five divisions.

The US ambassador had done the same weeks earlier, urging Soviet troops to complete their pullout and predicting the collapse of the Afghan government.
 

Anxious voices
 

These were the dying days of the Soviet empire in the harsh winter of 1989. We didn't know it then. But we felt Kabul was in the eye of the storm.

Every day, several times a day, I was asked, in whispered anxious voices, by foreigners and Afghans: "Are you leaving? Do you think it's safe to stay? When will Najib go?" Najib is what many called the Soviet-backed president,
Najibullah.

Najibullah - 'he was very strong'

Some said he was a murderer, from his days heading the infamous KGB-trained Khad secret service. His nickname was the Ox - he was a burly man with a big voice and a barrel chest. He declared, to anyone who would listen, he wasn't going anywhere.

Not many believed him then. In neighbouring Pakistan, mujahideen rebels, backed by the might of the United States, the money of Saudi Arabia, and the efforts of Pakistan, bickered over the formation of an alternative government.

Earlier, while in Islamabad, I was warned by some mujahideen leaders to be careful in Kabul. They later sent safe-passage letters so that when they entered I would not be harmed. For them, it was only a matter of weeks.

How hard it was then to know if they were right or Najibullah was.
 

City cut off
 

Even Soviet officials heightened this sense of siege, speaking of 30,000 mujahideen fighters just beyond the snow-capped mountains that encircle this city. The rockets fell on Kabul every day. But was Kabul itself even close to falling?
 

Afghans still worry about the future, foreigners still ask if it's safe to stay

In recent weeks, I've been calling Afghans who were the president's closest advisers then. "Was Najib really that strong then?" I asked one former aide. "Najib wasn't just strong," he insisted, "he was very strong".

Kabul in 1988 was isolated - by Cold War rivalries, and often cut off by snow that blocked any road or flight out of the city. There were of course no mobile telephones or internet then, just a small number of clattering telex machines and only three international telephone lines.

For some reason, many calls were routed through Glasgow. So every day, in my fourth floor room in a gloomy hilltop hotel, I spent a lot of time talking to Scottish telephone operators.

Three years later President Najibullah's rule finally ended. He was brought down by intrigues within his own party and in Moscow, an ill-fated UN process, and double-dealing by rival mujahideen commanders. They eventually took over Kabul and destroyed large parts of it.
 

Body hung
 

The president still did not manage to leave as his regime collapsed around him. He took refuge in a UN compound. And when the Taleban stormed into Kabul in 1996, he was urged to flee, but with his trademark confidence, he insisted: "I know my people, I will stay."
 

Life is still hard for children in Kabul

Vengeful Taleban fighters killed him and hung his body at a roundabout alongside his brother.

That was then, and this is now. On Kabul's freezing winter streets Afghan urchins press smudged faces against car windows peddling photographs of Afghan leaders including Najibullah. Copies of his speeches now do a brisk trade in the market - they are admired by some Afghans for their wisdom and wit.

The violence has not gone either. Now it is Taleban suicide bombs rather than mujahideen rockets which terrorise this city.

Afghans still worry about the future, foreigners still ask if it is safe to stay. And, just as many once asked how long President Najibullah could cling on to power, now they ask whether an embattled President Karzai will be elected again - and Western governments, including a new administration in Washington, raise questions about his rule.

Twenty years on Kabul remains threatened by rebels, cradled by the Hindu Kush, still very much in the eye of the storm.