Were mines or torpedoes more effective in World War I, and were torpedoes more effective in World War I or World War II?
Short answerMines had the greater effect in World War I. Torpedoes probably had greater effect in World War II, when they were used more extensively, although mines still caused important losses.
NotesSea mines receive the stronger assessment for World War I. Torpedoes probably had greater impact in World War II because their use was more extensive. That shift includes greater emphasis on torpedo attacks than on submarine minelaying. Mines remained dangerous in World War II and still accounted for well-known losses.