War

A war was an armed conflict between two or more groups.

Thousands of years ago

 * Great Psionic War (c. 500,000 BC)

19th century

 * Napoleonic Wars
 * American Civil War (1861-1865)

20th century

 * World War I (1914-1918)
 * World War II (1939-1945)
 * Earth Cold War (1945-1991)
 * Korean War (1950-1953)
 * Vietnam War (1955-1975)
 * Eugenics Wars (1992-1996)

21st century

 * Iraq War (2003-2011)
 * World War III (2026-2053)

22nd century

 * Earth-Kzin Wars
 * Earth-Romulan War (2155-2160)
 * Romulan-Haakonan War (2156-2157)
 * Federation-Tarn War (2160s)

23rd century

 * Federation-Klingon Cold War (2218-2293)
 * Romulan Civil War (2276)
 * Federation-Klingon War (2285)

24th century

 * Federation-Cardassian War (2355-2359)
 * Tzenkethi War
 * Klingon Civil War (2367-2368)
 * Klingon-Cardassian War (2372-2373)
 * Federation-Klingon War (2372-2373)
 * Dominion War (2373-2375)
 * Selelvian War (2376)