A conflict resulting from rivalries between Paraguay, Uruguay, Brazil, and Argentina. The Paraguayan President Francisco Solano López, alarmed by Brazilian intervention in Uruguay and harbouring desires for Paraguayan territorial expansion and access to the sea, initiated hostilities against Brazil in 1864. Despite traditional rivalry between Brazil and Argentina, the latter joined Brazil and its puppet government in Uruguay in the Triple Alliance pact (May 1865) against Paraguay. Paraguay’s well-trained army of 600,000 men did not prove equal to the task, and López’s death in March 1870 ended one of the most destructive wars in Latin American history. In addition to losing more than half of its population, Paraguay was also stripped of considerable territory as a result of the war.