Operation Three Spears (Span: Operación Tres Lanzas) was the Argentinean military operational name for the three-pronged invasion of the Cisplatina province as a part of Operation Fireball in late March and early April 1980. Three Spears involved an amphibious landing along the Atlantic coast and across the Rio de la Plata from Buenos Aires and its suburbs, a traditional infantry crossing over the Uruguay River on the far western flank, and paratrooper invasion in central Cisplatina to cut off retreating Brazilian soldiers and eliminate supply lines. The attack caught Brazilian troops in and around Montevideo off guard, making Three Spears a strategic and tactical success after nine days of fighting. The plan for Three Spears had existed for months and was the exclusive operational package