Answer
Mohammad Najibullah replaced Babrak Karmal in 1986 with the help of the Soviet Union. Najibullah was a communist and a Soviet puppet, and he served as the President of Afghanistan from 1986 to 1992. During his time in office, he attempted to negotiate a peace agreement with the Mujahideen, but these efforts failed. In 1992, the Mujahideen overthrew Najibullah's government and he was forced to flee the country.