How maritime advantages were squandered in Spain

British and French reluctance to intervene left the Republic constrained, while German and Italian forces observed Republican movements, supported submarine attacks, and protected Nationalist access. Soviet advisers are criticised for prioritising the security of Soviet supply ships instead of exploiting broader maritime advantages. The Republic therefore failed to turn control of much of the operational fleet into sustained pressure on Nationalist reinforcement and supply. Sea power could not decide every political outcome on its own. Its effect ashore still depended on how commanders used an existing advantage.