What was the bloodiest war in South America in the 20th Century?
The Chaco War (1932–1935) between Bolivia and Paraguay was fought over control of the northern part of the Gran Chaco, which was thought to be rich in oil. It was a war between two poor countries, which had lost territory to neighbors in 19th-century wars. Bolivian penetration in the region went unopposed until 1927, when the first blood was shed: Lt. Rojas Silva was shot and killed in suspicious circumstances when his army foot patrol and native guides were taken prisoners, The Bolivian government formally regretted the death, but the Paraguayan public opinion called it "murder". Talks held in Buenos Aires failed and hostilities escalated. Actual war started In 1932 when Bolivia captured and burned a Paraguayan fort. Although Bolivia was stronger economically and had larger, better-equipped army, a series of factors led to its defeat . Peace treaties granted 2/3 of the disputed territories to Paraguay.
Casualties: Bolivia 50,000–80,000, Paraguay, 35,000–50,000
The Falklands War - 2 April/14 June 1982 - Argentina invaded the Falkland Islands in an attempt to establish the sovereignty. British government sent a naval task force and made an assault than ended in Argentina surrendering. Casualties: 649 (Argentina) 255 (British)
The Cenepa War - a conflict between Ecuador and Peru, fought over control of an area in Peruvian territory (26 Jan-28 Feb 1995) Casualties: 60 (Peru) (Ecuador).
The War of the Generals was a civil war fought in Ecuador from 1912 to 1914