"In no field is the Soviet claim to pre-eminence more clearly justified than that of mine warfare. The Russians aided in the establishment in the 1840s of the first factory for the production of mines; in the Baltic during the Crimean War they made the first extensive use of mines; they established the first school of mine warfare; and before the year 1900 they constructed a class of ships designed as minelayers from the keel up. During six wars - the Crimean, the War of 1878 with Turkey, the Russo-Japanese War, World War I, the Civil War, and World War II - mine warfare has played the leading role in Russian naval strategy. If wars by proxy are considered, a seventh conflict, the Korean War, might be added to the above listing."