The final practical test is where a navy expects its submarines and surface ships to operate. A submarine intended to remain near its own coast as a submerged defensive barrier may gain little from the cost of nuclear propulsion. Long-distance deployment and integration into allied task groups create a much stronger case because sustained presence and transit endurance become central to the mission. Nuclear propulsion is worthwhile only when that capability justifies the expensive national system required to support it.
Notable Point · 40:50-42:21
The operating-range test for nuclear submarines
Local coastal defense may favor diesel-electric submarines, while distant deployments and allied task groups make nuclear endurance more valuable.