The Dardanelles Strait is a narrow passage of water in northwestern Turkey that connects the Aegean Sea with the Sea of Marmara. The strait is a strategic location. During World War I, First Lord of the Admiralty Winston Churchill led an attack against Turkish soldiers during the Gallipoli Campaign of 1915. The assault was Britain's attempt to reopen the Dardanelles Strait to encourage some of the neutral Balkan states to join the Allies. Britain's attempt failed, with losses amounting to three ships and 700 lives, due to frequently faulty intelligence, uninspired leadership, and an inspired defense mounted by forces under Liman von Sanders' command. The strait also was one of the original targets for Truman Doctrine aid to head off a 1949 communist incursion into Turkey, as the policy of containment began to take shape.