An additional J-class destroyer would not have changed the outcome of the war by itself, but its availability could have affected several successive operations. Even the rapidly built American Essex-class carriers required years between ordering and service, so ships already commissioned or under construction fought much of the war. The J, K and Tribal classes repeatedly received dangerous missions because they were the most capable ships available to attempt them. Their losses therefore need to be considered alongside the risks of their assignments. Extra destroyers could allow another operation, strengthen a group's air defence or spread attacks across more targets. If that reduced losses, the benefit would carry into the next operation. Interrupting construction could similarly weaken the fleet across several later phases of the war.
Notable Point · 27:42-31:02
Why prewar destroyer numbers shaped the whole war
Cancelling even one prewar destroyer mattered because wartime replacements required years and the available frontline ships repeatedly absorbed the riskiest missions.