Conflict Combatant 1 Combatant 2 Results Notable battles Siege of Colonia del Sacramento (1704 - War of the Spanish Succession )[ 1] Buenos Aires Kingdom of Spain Victory: Spanish forces of the Portuguese colonial abandoned Colonia del Sacramento Anglo-Spanish War (1796 –1808) United Kingdom Spanish victory Second Banda Oriental campaign (1812-1814) Spanish Empire United Provinces of the Río de la Plata United Provinces of the Río de la Plata victory Portuguese conquest of the Banda Oriental (1816–1820) United Kingdom of Portugal, Brazil and the Algarves Luso-Brazilian victory War of Independence of Brazil (1822 - 1825) Kingdom of Portugal Empire of Brazil Brazilian victory Cisplatine War (1825–1828) Río de la Plata Thirty-Three Orientals Brazil Stalemate Uruguayan Civil War (1839–1852) Colorados Unitarians Brazil Entre Ríos Corrientes France United Kingdom Blancos Argentina Federalists Colorado victory Imposition of the Colorados in Uruguay Platine War (1845–1852) Brazil Uruguay Paraguay Argentine Rebels Argentina Victory Argentine clout over the Platine region ends Brazilian hegemony in the Platine region Uruguayan War (1864–1865) Uruguay Blancos Federalists Brazil Colorados Unitarians Argentina Defeat Colorados takeover, regime change in Uruguay Paraguayan War (1864–1870) Brazil Argentina Uruguay Paraguay Victory Allied occupation of Paraguay Revolution of the Lances (1870–1872) Colorados Blancos Blanco victory Agreement of power-sharing reached Revolution of 1904 (1904) Colorados Blancos Colorado victory World War II (1945) United States Soviet Union United Kingdom China France Poland Canada Australia New Zealand India South Africa Yugoslavia Greece Denmark Norway Netherlands Belgium Luxembourg Czechoslovakia Brazil Mexico Chile Bolivia Colombia Ecuador Paraguay Peru Venezuela Uruguay Argentina Germany Japan Italy Hungary Romania Bulgaria Croatia Slovakia Finland Thailand Manchukuo Mengjiang Victory