The rule of four and sustainable fleet readiness

Why buy four Bristol-type missile cruisers rather than eight, with two for each carrier?

The proposed budget supports one missile cruiser per aviation cruiser, with enough complete groups to maintain availability.

The reply limits the missile-cruiser force to four to keep the counterfactual program affordable and discreet. Each task group would contain an aviation cruiser, a missile cruiser, three or four destroyers, and about six anti-submarine frigates. The argument then turns to the cancelled fifth Resolution-class ballistic-missile submarine. Completing that boat is proposed as a precedent for recognizing that a continuous deterrent needs more hulls than are deployed at once. The wider aim is to establish a rule of four for conventional forces through the stronger availability argument made for five ballistic-missile submarines. These are proposed procurement ratios, rather than a claim that every ship can be counted as operational simultaneously.