Armed Forces of the Democratic Republic of Afghanistan in the context of "Northern Alliance"

The Soviet–Afghan War took place in Afghanistan from December 1979 to February 1989. Marking the beginning of the 46-year-long Afghan conflict, it saw the Soviet Union and the Afghan military fight against the rebelling Afghan mujahideen, aided by Pakistan. While they were backed by various countries and organizations, the majority of the mujahideen's support came from Pakistan, the United States (as part of Operation Cyclone), the United Kingdom, China, Iran, and the Arab states of the Persian Gulf, in addition to a large influx of foreign fighters known as the Afghan Arabs. American and British involvement on the side of the mujahideen escalated the Cold War, ending a short period of relaxed Soviet Union–United States relations.

Combat took place throughout the 1980s, mostly in the Afghan countryside, as most of the country's cities remained under Soviet control. The conflict resulted in the deaths of one to three million Afghans, while millions more fled from the country as refugees; most externally displaced Afghans sought refuge in Pakistan and in Iran. Between 6.5 and 11.5% of Afghanistan's population of 13.5 million people (per the 1979 census) is estimated to have been killed over the course of the Soviet–Afghan War. The decade-long confrontation between the mujahideen and the Soviet and Afghan militaries inflicted grave destruction throughout Afghanistan, and has been cited by scholars as a significant factor contributing to the dissolution of the Soviet Union in 1991; it is for this reason that the conflict is sometimes referred to as "the Soviet Union's Vietnam".

Operation Cyclone was the code name for the United States Central Intelligence Agency (CIA) program to arm and finance the Afghan mujahideen in Afghanistan from 1979 to 1992, prior to and during the military intervention by the USSR in support of the Democratic Republic of Afghanistan. The mujahideen were also supported by Britain's MI6, who conducted their own separate covert actions. The program leaned heavily towards supporting militant Islamic groups, including groups with jihadist ties, that were favored by the regime of Muhammad Zia-ul-Haq in neighboring Pakistan, rather than other, less ideological Afghan resistance groups that had also been fighting the Soviet-oriented Democratic Republic of Afghanistan administration since before the Soviet intervention.

Operation Cyclone was one of the longest and most expensive covert CIA operations ever undertaken. Funding officially began with $695,000 in mid-1979, was increased dramatically to $20–$30 million per year in 1980, and rose to $630 million per year in 1987, described as the "biggest bequest to any Third World insurgency". The first CIA-supplied weapons were antique British Lee–Enfield rifles shipped out in December 1979 and by September 1986, the program included U.S.-origin state-of-the-art weaponry, such as FIM-92 Stinger surface-to-air missiles, some 2,300 of which were ultimately shipped into Afghanistan. Funding continued (albeit reduced) after the 1989 Soviet withdrawal, as the mujahideen continued to battle the Armed Forces of the Democratic Republic of Afghanistan during the First Afghan Civil War.

The Khalq (Dari/Pashto: خلق, lit. 'masses' or 'people') was a faction of the People's Democratic Party of Afghanistan (PDPA). Its historical de facto leaders were Nur Muhammad Taraki (1967–1979), Hafizullah Amin (1979) It was also the name of the leftist newspaper produced by the same movement. The Khalq wing was formed in 1967 after the split of the party due to bitter resentment with the rival Parcham faction which had a differing revolutionary strategy.

It was made up primarily of Pashtuns from rural backgrounds. Its leaders preferred a mass organization approach and advocated class struggle to overthrow the system to bring about political, economic and social changes. They would rule the Democratic Republic of Afghanistan that was formed as a result of the Saur Revolution in 1978. The Khalqists introduced radical reforms and carried out brutal crackdowns on dissent turning Afghanistan into a police state run by the AGSA (and later KAM). The Khalqist crackdowns encouraged the rebellion of the religious and ethnic minority segments present in the Afghan society, which led more people joining exiled Islamist parties in Pakistan, however these rebellions did not pose an existential threat to their rule due to Khalq's large support base within the Armed Forces. Khalqist rule would be ended following Soviet military intervention in December 1979 overthrowing Hafizullah Amin.