The Falklands War (Spanish: Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands, and its territorial dependency, the South Georgia and the South Sandwich Islands. It began on Friday, 2 April, when Argentina invaded and occupied the Falkland Islands (and, the following day, South Georgia and the South Sandwich Islands) in an attempt to establish the sovereignty it had claimed over them. On 5 April, the British government dispatched a naval task force to engage the Argentine Navy and Air Force before making an amphibious assault on the islands. The conflict lasted 74 days and ended with the Argentine surrender on 14 June, returning the islands to British control. In total, 649 Argentine military personnel, 255 British military personnel, and three Falkland Islanders died during the hostilities.
The conflict was a major episode in the protracted confrontation over the territories' sovereignty. Argentina asserted (and maintains) that the islands are Argentine territory, and the Argentine government thus characterised its military action as the reclamation of its own territory. The British government regarded the action as an invasion of a territory that had been a Crown colony since 1841. Falkland Islanders, who have inhabited the islands since the early 19th century, are predominantly descendants of British settlers, and strongly favour British sovereignty. Neither state officially declared war, although both governments declared the Islands a war zone. Hostilities were almost exclusively limited to the territories under dispute and the area of the South Atlantic where they lie.
The conflict has had a strong effect in both countries and has been the subject of various books, articles, films, and songs. Patriotic sentiment ran high in Argentina, but the outcome prompted large protests against the ruling military government, hastening its downfall. In the United Kingdom, the Conservative government, bolstered by the successful outcome, was re-elected with an increased majority the following year. The cultural and political effect of the conflict has been less in the UK than in Argentina, where it remains a common topic for discussion.
Diplomatic relations between the United Kingdom and Argentina were restored in 1989 following a meeting in Madrid, at which the two governments issued a joint statement. No change in either country's position regarding the sovereignty of the Falkland Islands was made explicit. In 1994, Argentina's claim to the territories was added to its constitution.
The war is also known as the Falklands Conflict, Falklands Crisis, Malvinas War, South Atlantic Conflict, and the Guerra del Atlántico Sur (Spanish for "South Atlantic War").