The last decade has reaffirmed that intervention and its close relative, disengagement, remain both important and very topical issues in international politics. A couple of examples will suffice. In January 1979, the Vietnamese army entered Kampuchea and overthrew the Pol Pot regime. At the end of the same year, Soviet troops crossed the border into Afghanistan and deposed the government of President Hafizullah Amin. Both Vietnam and the USSR denied they had intervened. The Vietnamese claimed they were ‘liberating’ the Kampuchean people from a tyrannical government, whilst the Soviets said they had simply responded to a repeated request for military assistance against ‘armed intervention by imperialist forces’. Now, nearly a decade later, Vietnam and the USSR have begun the process of extricating themselves from these military entanglements. In June 1988, Hanoi announced its intention to withdraw all its 100,000-strong troop contingent from Kampuchea by 1990. Meanwhile, the USSR, under the terms of a UN-mediated accord signed on 15 April 1988, had withdrawn all 115,000 of its troops from Afghanistan by February 1989.