Democratic Republic of Afghanistan

The Democratic Republic of Afghanistan, later known as the Republic of Afghanistan, was the left-wing led Afghan state from 1978 to 1992. It was bordered by Pakistan to the east and south, by Iran to the west, by the Soviet Union to the north, and by China to the northeast. Established by the People's Democratic Party of Afghanistan (PDPA) following the Saur Revolution in April 1978, it came to rely heavily on the Soviet Union for financial and military assistance and was therefore widely considered to be a Soviet satellite state. The PDPA's rise to power is seen as the beginning of the ongoing Afghan conflict, and the majority of the country's years in existence were marked by the Soviet–Afghan War. It collapsed by the end of the First Afghan Civil War in April 1992, having lasted only four months after the dissolution of the Soviet Union.

The PDPA began ruling Afghanistan after ousting the unelected autocrat Mohammad Daoud Khan, who had become president by leading the 1973 Afghan coup d'état; he was succeeded by Nur Muhammad Taraki as the head of state and government on 30 April 1978. Both Taraki and his successor Hafizullah Amin, who had organized the Saur Revolution as the General Secretary of the PDPA, introduced several contentious reforms during their time in office, such as land and marriage reforms and an enforced policy of de-Islamization vis-à-vis the promotion of socialism. Amin, in particular, built upon Khan's reforms with even more radical legislation for Afghanistan's conservative Muslim society, such as universal education and equal rights for women. Soon afterwards, a power struggle began between two PDPA factions: the hardline Khalq, led by Taraki and Amin; and the moderate Parcham, led by Babrak Karmal. The Khalqists eventually emerged victorious and subsequently purged the bulk of the Parchamite ranks, while also exiling most of the prominent Parcham leaders to the Soviet Union and the Eastern Bloc.

Following the Khalq–Parcham conflict, a power struggle arose within the Khalq faction itself, as Taraki and Amin increasingly contested each other's influence. Amin gained the upper hand among the Khalqists and later had Taraki killed on his orders. Due to his earlier reforms, however, Amin's rule proved to be unpopular throughout most of Afghanistan, with the country's emerging instability prompting the Soviet government to begin planning for a direct military intervention in favour of the Parchamites. On 27 December 1979, the Soviet Union launched Operation Storm-333, assaulting the Tajbeg Palace in Kabul and assassinating Amin, who was then replaced by Karmal. The Karmal era, which lasted from 1979 to 1986, was marked by the height of the Soviet–Afghan War. As the Soviet and Afghan militaries fought against the Afghan mujahideen, which had been bolstered by military aid from the Muslim world and the Western Bloc, the country rapidly destabilized, resulting in widespread civilian casualties and the creation of millions of refugees, most of whom fled to Pakistan and Iran. In April 1980, the "Fundamental Principles" (comprising a constitution) were introduced by Karmal's administration, and several non-PDPA members were allowed into the government to broaden the country's support base. However, these policies ultimately failed to bring peace to Afghanistan, and in 1986, Karmal was succeeded by Mohammad Najibullah.

Najibullah pursued a policy known as National Reconciliation: a new constitution was introduced in 1987 and democratic elections were held in 1988, though they were boycotted by the mujahideen. After almost a decade of warfare, the Soviet Union withdrew from Afghanistan in February 1989, but continued to back the PDPA, which was facing mounting resistance from the opposition. By 1990, another constitution was introduced, stating that Afghanistan's true nature was that of an Islamic republic and transforming the PDPA into the Watan Party. On the military front, the government still proved to be capable of performing in open combat, as demonstrated in the Battle of Jalalabad. However, with growing internal difficulties, such as the 1990 Khalqist coup attempt, and the dissolution of the Soviet Union in December 1991, the Najibullah government was unable to sustain itself and ultimately lost the First Afghan Civil War in April 1992, which, in turn, triggered the Second Afghan Civil War. Afghanistan eventually transitioned to an Islamic Republic which remained from 2004 to 2021.