A deterrent submarine already at sea avoids the escalatory signal created by sending one out only after a crisis begins. A submarine kept alongside for most of the time also offers less survivability. Three boats would usually provide one at sea, while four support continuous patrols and keep another available at short notice if the deployed boat develops a problem. Escorts and carriers face less predictable operational demands yet often have less numerical resilience. If Britain chooses to maintain a nuclear deterrent, its force structure needs to make that deterrent survivable and continuously available.
Notable Point · 1:28:36-1:31:12
Continuous deterrence as a force-generation lesson
Britain's four ballistic-missile submarines demonstrate why predictable maintenance and backup capacity require more platforms than the one visibly deployed.