I provide a list and tell me which are plausible and impalusible then maybe tell some wars that would work?
Major Wars
War for Southern Independence 1861-1864 vs. U.S.
Spainish-Confederate War 1871-1873 vs. Spain
Confederate-Nicragugian War 1895 vs. El Salvador, Coasta Rica, and Nicragugian Rebels
World War 1 1914-1919 vs. England, Russia, France, and U.S.(1918)
World War 2 1939-1945 vs. England, Russia, U.S.(1941)
Andean War 1957 vs. Peru, Chile, and Argentinia
Mexican-Confederate War 1979-1989 vs. Mexico
Confederate-Afghanistan War 2001 vs. Taliban and Al-Queda
Iraqi War 2003 vs. Iraq
Proxy Wars
Korean War 1950-1953- helping the North Koreans
Vietnam War 1965-1977- helping North Vietnam
U.N. Peacekeeping Missions(member in 1950)
Ethoipia in 1984
Somalili in 1993
Bosnia and Herzgovinia in 1997-1998
Kosovo in 1998-1999