Replacement begins with more than a ship's age

A design life does not create an automatic retirement date, especially when a state cannot agree on the replacement. Russia's repeated refurbishment of Soviet-era large surface combatants shows how an old fleet can persist after the capacity to build equivalent new ships has faded. Russian yards retained important competencies in icebreakers and submarines, but those specialisms do not by themselves restore the infrastructure and supporting resources needed for new cruisers or carriers. Nor can a frigate design simply be scaled into a much larger combatant without recovering those capabilities. The condition of the existing ship therefore matters alongside the industrial feasibility of producing its successor.