The Argentinean occupation of Uruguay during the Brazilian War refers to the placement of Argentinean forces on Uruguayan soil from 1980 until their withdrawal in the summer of 1984, when use of Uruguayan territory to conduct operations in Brazil was no longer needed. The occupation was justified as being both preemptive and offensive; that Argentina concluded, with controversial intelligence, that if it entered the war Brazil would move across the Rio Negro border between Uruguay and its Cisplatina province to secure a forward base with which to attack Buenos Aires, and that in order to launch offensives into Brazil it needed to transit Uruguayan territory. The occupation began with the Three Spears operations including an amphibious landing that caught the Uruguayan military entirely off guard; the civilian government resigned on March 25th in humiliation after Uruguay was overrun within 24 hours and Montevideo under occupation. A "caretaker government" that cooperated with Argentina was assembled out of technocrats and military officials. Argentinean troops were under strict orders to be respectful of their hosts and total forces in Uruguay never numbered very many continuously, due to needs on the front; Brazil's government was just as detested as Argentina's by the Uruguayan populace and Brazilian saboteurs were unable to create more than a nuisance, besides stray assassinations and kidnappings. Several controversial incidents occurred, however; the shooting of three farmers near a rural checkpoint in 1981, Argentina's imposition of an unpopular curfew and reluctance to turn violators over to Uruguay's National Police, and an incident in Punta del Este at the Discoteca Nueva in 1983, where Argentinean soldiers allegedly raped multiple women and started a gunfight that wound up killing seven people. The final incident sparked street protests that concluded with Argentina sharply drawing down their troop presence in the country that year and withdrawing the final soldiers the next August.
The occupation was regarded as illegal by much of the world and severely damaged Argentina's prestige, even with its American and Colombian allies; in 2003, Argentinean President Eduardo Duhalde apologized for the occupation on the 20th anniversary of the Discoteca Nueva incident and in 2008 Argentina paid an indemnity reparation to Uruguay worth nearly $1 billion US dollars. The conduct of Argentina as an "occupying force" remains controversial between the two countries today despite improving relations.