The Soviet Union invaded Afghanistan in December 1979 primarily to support the faltering communist government of Afghanistan, led by the People's Democratic Party of Afghanistan (PDPA), and to prevent the spread of Islamic radicalism which they feared could spill over into Soviet Central Asian republics. The Soviets saw the Afghan communist regime as unstable and facing growing insurgency from the mujahideen, who were backed by the United States and other countries. Key reasons included:
- The Soviet leadership wanted to uphold the Brezhnev Doctrine, which justified intervention in socialist countries to protect socialism.
- They aimed to stabilize Afghanistan by replacing the radical communist leader Hafizullah Amin with a more moderate leader, Babrak Karmal.
- The Soviets feared that an Islamist regime in Afghanistan would inspire radical Islamic movements in nearby Soviet Muslim regions.
- They believed the United States and Pakistan were supporting the insurgency to destabilize Soviet influence in Central Asia.
- The invasion was also motivated by Cold War dynamics, as Afghanistan was a strategic neighbor and its loss could shift regional power toward Western influence.
The Soviet Union initially expected a short intervention but ended up embroiled in a prolonged and costly conflict lasting nearly a decade, with heavy losses and no decisive victory, ultimately contributing to internal Soviet weaknesses. In summary, the invasion was driven by a mix of geopolitical strategy during the Cold War, ideological commitments to socialism, fears of Islamic extremism spreading into Soviet territory, and efforts to maintain regional influence through a friendly government in Afghanistan.
