Nothing could be further from the truth: far from 'forgetting' or 'abandoning' Afghanistan, the West, in violation of the April 1988 UN agreement on a Soviet withdrawal, continued to arm and finance the rebels and in the end brought down the reforming communist regime. In April 1988 the 'West', i.e. the US, Britain and its allies, Egypt and Pakistan, signed an agreement to stop supplying the Islamist guerrillas in Afghanistan in return for a withdrawal of Soviet forces.
The Soviets left by February 1989, but aid to the guerrillas continued with the intention of forcing a collapse of the communist regime in Kabul. The US at the same time pressed hard for a cutoff in Soviet support for the Afghan regime after their troop withdrawal, but this was not successful until the change of government in Moscow following the failed coup of August 1991; then, in a deal brokered by US Secretary of State James Baker, Moscow cut off all aid to its former ally in Kabul.
The regime of President Najibullah, who had held power since 1987, fell the following April.
-number 54 from Fred Halliday's 100 Myths about the Middle East (SAQI, 2005)