On the night of October 25 to 26 (November 7 to 8), 1912, Russian naval minister I. K. Grigorovich urgently telegraphed Nicholas II: “I most humbly request your Imperial Majesty’s permission to allow the commander of the Black Sea naval forces to have direct communication with our ambassador in Turkey for the expulsion of an unlimited number of warships or even the entire squadron...” On the morning of October 26 (November 8), Nicholas II replied: “From the very beginning, the requested measure, which I agreed to, should have been applied.” However, World War I began two years later. What role did the Bosphorus and Dardanelles play for Russia and who pushed the tsarist government to enter the Great War? Based on unpublished archival materials, Soviet and foreign publications of diplomatic documents, the author examined the problem of the Black Sea Straits in the context of the Anglo-Russian agreement of 1907, the Bosnian crisis, the Italian- the Turkish War, the Balkan Wars, the mission of Liman von Sanders in Constantinople and the preparations for the First World War.