044. Warships sailing the Turkish straits: international law at work

The Black Sea is of crucial economic and strategic importance for its littoral states and so are of course the Turkish straits (Bosporus and the Dardanelles). Day in day out, year in year out, they remain open for traffic, connecting the Black Sea with the Mediterranean Sea and from there to the rest of the world. Every day 100’s of ships sail by, just paying a nominal fee for the pilot vessel that guides them through the straits. I can see the ships from my office, for any Dutch (we love the sea) a terrific sight.

As all other straits and narrow sea-lanes on this planet, the Bosporus and the Dardanelles are regulated by International Law. As a student of International maritime law myself, it is satisfying to see International Law (one of the pillars of the Dutch foreign policy) at work. In cases like the Turkish straits, international law works wonderfully well and is respected to the letter by all stakeholders. We should be happy for this. In a region fraught with too many conflicts we definitely don’t need another one over maritime transit through the Bosporus or the Dardanelles.


From competition to cooperation

The Black Sea region is much more than an economic cross road of continents. It is also the meeting place of many civilizations and of the most strategically important parts in the world. Regrettably, it was and is also a focal point for armed conflicts. History shows us for example that the Black Sea has been an area of competition between Turkey and Russia and the source of bloody wars for hundreds of years.

The Montreux Convention (1936)

Passage of ships through the Bosporus and the Dardanelles is regulated by a 1936 multinational treaty, the Montreux Convention. This treaty gave Turkey control of the straits, which makes sense as the straits are fully within its territory. It was signed by Turkey, the USSR, Britain, Australia, Bulgaria, France, Greece, Romania, Yugoslavia and Japan (with reservations).

The Montreux Convention/Civilian Vessels

For civilian vessels of any flag, their peacetime access is free and unlimited, “with any kind of cargo,” as stated in Article 2 of the treaty (thus allowing military goods to be transshipped as well….)

The agreement guarantees access from Russia’s only year-round warm water ports to major international markets. Russia is world’s largest exporter of gas and fourth-largest exporter of wheat. The Turkish straits are one of its most crucial export gateways. Approximately 3.0 million bbl/d of crude oil flows through the Bosporus and the Dardanelles (2013).

The Montreux Convention/military vessels

For me, the most fascinating aspects are the warships. Regularly I see them, even submarines, passing by in the waters close to my home.

The visit of Dutch Frigate HM Tromp at the end of July 2015 in Istanbul, just coming back from a 21 day NATO-exercise in the Black Sea, was a good reason for me to have a look at the Montreux Convention again.

Why, for example, was the Dutch frigate 21 days in the Black Sea and not 30 or 40? Because the Montreux Convention forbids a longer stay… Concerning military matters it is a detailed convention indeed, which is probably much contributing to its success.


Some warship related stipulations in the Montreux Convention:

  • The treaty limits the access of warships from non-Black Sea nations, but allows Russia and other Black Sea states to move warships through the Turkish Straits to the Mediterranean Sea with few restrictions;
  • The convention also restricts outside navies’ access to the Turkish Straits and Black Sea to 21 straight days per warship, and to a maximum aggregate tonnage of 45,000 tons, with any one vessel no heavier than 15,000 tons. Non-Black Sea states must also give Turkey a 15-day notice before sending warships through the straits;
  • Turkey is the custodian of the straits;
  • In case of a war “belligerent powers” would be banned from the Straits. That’s what happened during World War II, when Turkey remained neutral and neither Germany nor the USSR could use the Bosporus and the Dardanelles;
  • Aircraft carriers of any flag are banned from the Turkish Straits, both in times of peace and of war.

So when you happen to see a war ship slowly sailing through the Turkish straits, think of Montreux and its 1936 Convention; almost 80 years old, but as relevant today as it was then.

(C) Featured image:  2009 Ivan Safyan Abrams (Flickr)

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