A year ago the rumble of Russian tanks invading Afghanistan was met by a chorus of condemnation from around the world. Jeremy Paxman reports from the Afghanistan-Pakistan border on what has happened since - the military and diplomatic price the Russians are paying, the effectiveness of Afghan guerrilla warfare and the plight of more than a million Afghan refugees. With the use of exclusive film, photographs and the testimony of recent refugees, he pieces together a picture of life in Kabul under Russian occupation.