Aircraft carriers play a vital part in our defence

sir – While critics are right to challenge the size and cost of the Royal Navy’s two new aircraft carriers, it would be foolish and wasteful to consider selling off these ships just as the final vessel enters service (Brexit Supplement, January 31).

The analogy to battleships during the Second World War is tenuous at best, since there is no question that aircraft and drones will remain at the centre of high-end warfare for decades to come. Instead, the key issue is how many aircraft and how many sailors we should choose to risk on board these carriers.

Critics point to the vulnerability of the two new carriers, but in reality they are less vulnerable to attack than the two shore airbases upon which Britain relies for its home air defences. A Russian submarine loitering off the coast of Britain could render these shore airfields (and their Typhoon jets) unusable within minutes with a conventional cruise missile strike.

The Russians or the Chinese (or indeed the Iranians) could, in a time of rising tension, sink a carrier or perhaps several; but that would pass a threshold and trigger severe repercussions. Nato possesses 13 large aircraft carriers, a similar number of medium-sized carriers and a sizeable submarine fleet with which to retaliate.

Military deterrence is all about containing adversaries by limiting their scope to manoeuvre without starting a major conflict. Large aircraft carriers have a key role to play in that strategy. Dr Mark Campbell-roddis

Dunblane, Perthshire