If HMS Vanguard had not been scrapped in the 1960s, could she have served in the Falklands War?
Short answerPotentially; survival through the 1970s and a Kirov-era justification could keep her available for 1982.
NotesVanguard would first have to survive both the 1960s and the difficult years before a new strategic rationale appeared. Construction of the Soviet Kirov class during the 1970s could provide a reason to retain her. Her size and power-generation capacity would leave more room for surface-to-air missiles and other modifications than the Tiger-class cruisers possessed. A Tiger-style conversion could therefore be more practical aboard the larger battleship. If those changes kept her available into 1982, Falklands service would be possible.