Would a battleship's 13-inch armour prevent damage from a Harpoon missile?
Short answerFailure to penetrate would not necessarily prevent dangerous shock behind the armour. A separate penetration claim depends on fitting an unspecified suitable warhead.
NotesThe claim that Harpoon might not penetrate a 13-inch armour belt prompts a distinction between penetration and damage behind the plate. One response argues that the impact could still transmit dangerous shock to people on the protected side. Clarke disputes the assumed penetration limit and adds that a Harpoon fitted with the right warhead could penetrate even Yamato's turret face. The exchange does not specify that warhead or establish the performance of a standard missile against those plates.