Why North Korean destroyers and submarines serve different purposes

What naval development could maximise the Korean People's Navy's value in a war?

Diesel-electric submarines offer a wartime role, while destroyers provide visible deterrence and status. The submarine option still has limits.

North Korean destroyers are assessed chiefly as instruments of deterrence and visible naval standing. Surface ships can demonstrate presence in a way that a concealed submarine cannot. Diesel-electric submarines offer a wartime attack capability, though their limitations remain acknowledged. A submarine that reveals its position gives up concealment and needs to withdraw. Nuclear propulsion makes a sustained high-speed withdrawal easier than it is for a submarine whose batteries must be recharged.