Vanguard would not guarantee Falklands deterrence

Would a surviving HMS Vanguard have deterred the Argentine invasion of the Falklands?

Not necessarily; Argentine planners might convince themselves Britain would not deploy the ship or that she was no longer combat-ready.

A surviving Vanguard would not automatically prevent Argentina from invading the Falklands. Argentine planners could persuade themselves Britain would not send the ship, just as they discounted the carriers Britain actually possessed. They might also assume that an old battleship was poorly maintained or no longer a credible combat unit. Military capability does not guarantee deterrence when an opponent misreads readiness or political willingness.