You need an organic surface warfare capability that extends past the range of the gun - every major navy and more than a few minor ones have been fielding anti shipping missiles for the last thirty or forty years - why be the odd one out? There's nothing worse than bringing a gun to a missile fight.
Ian
Actually some USN ships are now relying on Standard, and the T42s relied on Sea Dart. The Helicopters do all the leg work, I not saying ships based Harpoon is as redundant at a 15" turret but when are they ever going to be fired at anything? Name me some targets we would fire them at??? Agreed they are very useful on the back of lorries fired at us.
But we have plenty left over from the T23/T22 so just fit them when in foreign waters like the French did with the A69 class.
Ask youself how many Harpoon/Exocet have been ship fired by the RN v how many Skua?? Which is the weapon of choice and why??