They won the war because of US support, the US provided them with weapons and money to carry out the war.
The Afghan War, also called the Russo-Afghan War or the Afghan-Soviet War, by the Afghan Islamist mujahideen, was the first phase of the extensive conflict of the Afghan Civil War. The conflict took place between April 1978 and April 1992, when the armed forces of the Democratic Republic of Afghanistan (RDA), supported by the Soviet Army, from December 1979 to January 1989, fought against the Mujahideen insurgents. groups of Afghan Islamic guerrillas supported by numerous foreign countries, highlighting the United States, who provided them with huge amounts of arms and money. The conflict is considered part of the Cold War.
