The Montreux Convention is signed in Switzerland, authorizing Turkey to fortify the Dardanelles and Bosphorus but guaranteeing free passage to ships of all nations in peacetime.
The Montreux Convention Regarding the Regime of the Straits, often known simply as the Montreux Convention, is an international agreement governing the Bosporus and Dardanelles Straits in Turkey. Signed on 20 July 1936 at the Montreux Palace in Switzerland, it went into effect on 9 November 1936, addressing the long running Straits Question over who should control the strategically vital link between the Black and Mediterranean Seas.The Montreux Convention regulates maritime traffic through the Black Sea. It guarantees "complete freedom" of passage for all civilian vessels during peacetime and permits Turkey to restrict the passage of navies not belonging to Black Sea states. Military vessels are limited in number, tonnage and weaponry, with specific provisions governing their mode of entry and duration of stay. Warships must provide advanced notification to Turkish authorities, which, in turn, must inform the parties to the Convention.While it was designed for a particular geopolitical context, and remains unchanged since its adoption, the Montreux Convention has endured as a "solid example of a rules-based international order", since most of its terms are still followed. However, there have been some controversies in its implementation, most notably the proposed Kanal Istanbul, which would provide another waterway from the Black Sea to the Sea of Marmara, thereby possibly circumventing the Convention.