"Spartan" was ordered to sail south for the Falkland Islands two days before the Argentine invasion of the islands on 30 March 1982. "Spartan" was the first vessel to arrive in the islands and began to enforce a maritime exclusion zone imposed by the British. Shortly after, "Spartan" sighted Argentine merchant shipping mining the harbour at Stanley, but was not ordered to attack. This was partly due to British concerns about escalating the war too early, but also to avoid scaring off more lucrative targets such as the Argentine aircraft carrier . On 1 May, "Spartan" was marking "Veinticinco de Mayo", from just outside the Argentinian limit, when the submarine was ordered away by the Northwood fleet command in England, rejecting the strong view of the task force commander, Admiral Woodward. He considered, as the highest ranking naval officer in the area, he should control the RN submarines in the area and potentially faced losing the war by the lack of local control in the battle zone In the following days "Veinticinco de Mayo" was therefore able to move, unchecked by the British nuclear submarines, and potentially launch an A-4Q Skyhawk attack from much closer range than possible from Argentinian airfields. Unlike , "Spartan" did not fire in anger during the Falklands War, though she did provide valuable reconnaissance to the British Task Force on Argentine aircraft movements.