Montreux Convention 1936
Geographically, Turkey straddles the boundary dividing Europe and Asia. Sitting astride the Dardanelles and the Bosporus, Turkey controls the warm-water naval access of Russia, the Ukraine, and the Commonwealth of Independent States (CIS). Control of the straits between the Black and the Mediterranean Seas has long been a matter of keen interest to Russia, as well as other nations bordering the
Black Sea. Historically, Russia has viewed such control as the sine qua non of its own sovereignty.
In 1936, the former signatories to the Treaty of Lausanne together with Yugoslavia and Australia met at Montreux, Switzerland to abolish the International Straits Commission and return the Straits zone (the Dardanelles, the Sea of Marmora, and Bosphorus) to Turkish military control. They allowed Turkey to remilitarize the straits, which had been prohibited under the 1923 Lausanne Convention as part of the peace treaty that finally formally ended the hostilities begun in 1914. The new Montreux Convention also modified the 1923 rules for the passage of vessels through these waters. The Montreux [not Montreaux] Convention of 1936 [20 July 1936, 173 LNTS 213,219] was ratified by Turkey, Great Britain, France, the USSR, Bulgaria, Greece, Germany, Yugoslavia, and Japan (with reservations). While the United States is not a signatory to the Convention, it has historically always complied with its provision.
Merchant shipping of any flag and with any cargo has freedom of transit in the straits during peacetime and during wartime whenever Turkey is not a belligerent. Turkey may, however, require merchant ships to stop at a station upon entering the straits for the purposes of sanitary and health control. During wartime when Turkey is a belligerent, merchant shipping of countries not at war with Turkey has freedom of transit of the straits so long as those countries maintain their obligation of neutrality (e.g. not to provide support to another belligerent). Turkey may require such ships to commence transiting the straits during daylight hours.
During peacetime, light surface vessels [defined as warships displacing more than 100 tons but not above 10,000 tons] of all powers may transit the straits after giving prior notice to Turkey as required by the Convention. Turkey may waive the notification requirement if the warships were transiting for the purpose of providing humanitarian assistance. The choice of "light surface vessels" as the largest warship allowed through the straits effectively kept the new German "pocket battleships" out of the Black Sea -- a primary goal of the Soviet negotiators.
Capital ships of Black Sea powers may transit the straits provided that they did so in accordance with the Convention. The Black Sea powers (the Soviet Union, Bulgaria, and Romania) had two additional options, one involving submarines and the other permitting their "capital ships" with a tonnage greater than 10,000 to transit the straits.
The Convention applies specific individual and aggregate tonnage and numbers limits. These limitations effectively preclude the transit of capital ships and submarines of non-Black Sea powers through the Straits, unless exempted under Article 17. Article 17 of the Convention permits a naval force of any tonnage or composition to pay a courtesy visit of limited duration to a port in the straits, at the invitation of the Turkish Government. In such instances, the tonnage and numbers limitations of the Convention do not apply. Warships of non-Black Sea powers may not remain in the Black Sea longer than 21 days.
In Annex II of the Convention, "capital Ships" are defined as "surface vessels of war, other than aircraft carriers . . . ." Aircraft carriers are a separate category defined as "surface vessels of war, whatever their displacement, designed or adapted primarily for the purpose of carrying and operating aircraft at sea." The Soviet Union proposed the general principle that the straits be closed to aircraft carriers. This was a significant departure from the Lausanne Convention, which had allowed their passage.
Russian aircraft carriers in the Black Sea were first seen as "aircraft transports" in the Imperial Russian Navy during the First World War. Often converted passenger liners, these ships would carry a number of seaplanes that would be hoisted overboard for launch and then recovered back onto the ship after they had returned and landed. On 06 February 1916 two such seaplane tenders launched a 10-aircraft attack on the Turkish Black Sea port of Zonguldak. Later in 1916 the Imperial Naval Air service attacked the Bulgarian seaport of Varna in the same manner. These seaplane tenders did not long survive the Revolution.
The regime governing the Turkish Straits, the Montreux Convention, was conceived in haste during the inter-war years. It had not been revised to keep pace with either technological or political changes. The definitions of the various classes of warships were taken verbatim from the London Naval Treaty of 25 March 1936 (the so-called Second London Naval Treaty). Though the USSR was not a party to this Treaty, the framers of the London Naval Treaty represented the leading naval powers of the era. They, and not the Soviets, excluded aircraft carriers from the capital ship category. Annex II of the Convention defines aircraft carriers as "surface vessels of war, whatever their displacement, designed or adapted primarily for the purpose of carying and operating aircraft at sea. The fitting of a landing-on or flying-off deck on any vessel of war, provided such vessel has not been designed or adapted primarily for the purpose of carrying and operating aircraft at sea, shall not cause any vessel to fitted to be classified in the category of aircraft-carrier."
On 7 August 1946, following Turkish elections, the Soviet Union renewed its demands for a revision of the Montreux Convention governing access to the Black Sea, and Soviet naval activity in the region began. The Soviet Union demanded that Turkey’s control of the strategic Dardanelles Strait, guaranteed by the Montreux Convention in 1936, be modified in Russia’s favor. Among other things, the Soviets wanted joint rights with Turkey to use bases in the straits. On 10 August 1946, the Turkish Premier reaffirmed Turkey's intent to continue opposition to the Soviet demands. The United States objected to the Soviet demands, and President Truman approved plans to send a naval task force into the eastern Mediterranean. In the coming months, US and UK naval activity in region greatly increased, and on 18 October, Turkey rejected the Soviet demands. In the same time period, the Communist insurgency in Greece grew dramatically.
According to Article 2 of the Montreaux Convention, merchantmen were guaranteed complete freedom of transit and navigation. This has not been superceded by the 1982 Law of the Sea Convention, whose Article 36(c) provides that its transit passage articles do not affect “the legal regime in straits in which passage is regulated in whole or part by long-standing international conventions in force specifically relating to such straits.” In the 1990s Turkey imposed new navigation rules for the Straits as part of its continuing effort to “sell” the Baku-Ceyhan export pipeline. Under these new rules Turkey can demand more advance notice for the passage of a vessel through the Straits. Turkey can also stop any vessel on legal grounds and can require more ships to use local pilots and Turkey can raise transit fees by a factor of five.