Longest Wars of the 20th Century

• The Vietnam War (1955–1975) — 20 years
• The Chinese Civil War (1927–1950) — 23 years
• The Soviet–Afghan War (1979–1989) — 10 years
• The Algerian War of Independence (1954–1962) — 8 years
• The Iran–Iraq War (1980–1988) — 8 years
• Guatemalan Civil War (1960–1996) — 36 years