The Bosporus straits are considered international waterways and Turkey is prohibited from restricting their use in peacetime. Turkish maritime authorities can check ships for sanitary conditions and safety and can charge tolls, but cannot stop their passage.
The 1936 Montreux Convention Regarding the Regime of the Turkish Straits came about due to the Turkish desire to remilitarize the Straits, which under the terms of the Lausanne Convention had been demilitarized. They also wanted the international Straits Commission created by the Lausanne Convention abolished, seeing it as a obstacle to Turkish sovereignty in their internal waters.
The representatives of ten nations attended the conference held in Montreux. The principal contendors were Britain, the Soviet Union and Turkey; the main issue was military - the passage of combatant vessels in war.
The Convention agreed to consists of 29 Articles, four annexes and one protocol. Articles 2 - 7 consider the passage of merchant ships. Articles 8 - 22 consider the passage of war vessels. The key principle of freedom of passage and navigation is stated in articles 1 and 2 of the Convention. Article 1 provides that "The High Contracting Parties recognise and affirm the principle of freedom of passage and navigation by sea in the Straits". Article 2 states that "In time of peace, merchant vessels shall enjoy complete freedom of passage and navigation in the Straits, by day and by night, under any flag with any kind of cargo."
The winners were the Turks - the remilitarization of the Straits, the abolition of the Straits Commission and the collective guarantee clause of the Lausanne Convention gave Turkey complete sovereignty over the Straits.
The Montreux Convention is still in effect, with Turkey the sole authority with the legal power to interpret the Convention. But Turkey must still adhere to the principles of international law and the United Nations Convention on the Law of the Sea (1982), this can cause problems as there are variances between the conventions.
