LST wartime scale versus LSD long-term influence

Which mattered more historically in the Second World War, the LST or the LSD?

The LST dominated wartime impact through sheer numbers, although the LSD became more influential in postwar amphibious force design.

For the war itself, the LST takes primacy because its enormous numbers made Allied amphibious operations possible. Wartime impact differs from design legacy. The purpose-built British LST Mark I pointed toward later amphibious concepts, while the broader-capability LSD became more important over the long term. The LST supplied mass wartime lift, and the LSD provided the stronger postwar design model.