Thank you for that link hora ( this one )
It's definitely the most useful contribution to this thread so far imo.
Although I fail to understand how the BBC can claim on the one hand, that in September '79 the Afghan president, quote : "Requests for large numbers of Soviet forces to combat the growing insurgency continue under Amin's administration", and then on the other, that in December the Soviet Union, quote : "decides to invade". Why is it an invasion - if the government of one country asks another to send combat troops ? 
Still never mind, it's pretty accurate chronology of key events. Although by far the most important one imo, is the last one :
1989 15 February: The USSR announces the departure of the last Soviet troops....... Civil war continues as the mujahideen push to overthrow Najibullah, who is eventually toppled in 1992.
This is hugely important because it speaks volumes about the political situation in Afghanistan at the time. It shows that despite receiving no further help and assistance from the Soviet Union, and facing an enemy heavily financed and armed to the teeth with some of the most advanced weaponry available in the world, Najibullah's secular government was able to remain in power for over 3 years.
It has been expected that Najibullah's government would collapse the moment that Soviet troops withdrew. But although the mujahideen controlled vast areas of the countryside, all the major Afghan cities remained in government hands for several years. This could only have been possible if Najibullah's secular government enjoyed widespread support amongst the Afghan population.
I have no doubt that if the corrupt Afghan government which we are now propping up in Kabul suddenly had to stand on it's own two feet, it wouldn't last 3 months - never mind 3 years. Which is precisely why we must stay and prop it up.
If instead of doing everything at our disposal to undermine and overthrow it, we had supported Mohammad Najibullah goverment's attempt to build a modern progressive society in which all it's citizens received basic rights such education and healthcare (we supported the mujahideen when it attacked schools teaching girls) today Afghanistan might be a stable secular country, instead of being one ruled by corrupt warlords, drug dealers, and religious lunatics.
It's all history and totally irrelevant now, you might argue. It isn't, the lessons are there to be learnt - still we are making the same mistakes.
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btw, despite being eventually overthrown by the mujahideen, Najibullah was, surprisingly, allowed to live freely in Kabul - no attempt was made to even arrest him. When Kabul fell to the Taliban about 4 years later, the Taliban beat Najibullah to death and hung his bloody body from traffic lights in the centre of Kabul. An act which drew widespread condemnation not only from the Muslim world, but also from his close ally India. And an act which we are, at least partially, responsible for.
