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Montreux Convention – a factor of stability or a catalyst for insecurity in the Black Sea Region

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Montreux Convention – a factor of stability or a catalyst for insecurity in the Black Sea Region-Autor: PhD. Ciorobea Constantin

The Black Sea region has been and continues to be an area of particular specificity with a number of unresolved issues, and the Russian Federation’s attack on Ukraine further complicates the situation in the region. This region has long been under the influence of the complex relationship between Russia and Turkey and the interests of the global powers of the time, and precarious stability has become the main feature of the area. These issues have generated the need for international regulation of transit through the Black Sea straits, addressed by the provisions of the Montreux Convention.
The “Convention on the Regime of the Straits of the Black Sea”, or “Montreux Convention” for short, was signed on 20.07.1936 by Turkey, Bulgaria, Romania, USSR, France, Great Britain, Greece, Japan, Yugoslavia, then Italy in 1938. Japan withdrew from the Convention after the Second World War. The USA has not ratified the Montreux Convention, but complies with its provisions. The Convention regulates the transit of ships through the Bosphorus and Dardanelles straits according to their type (warships or merchant vessels) and according to four situations, namely peacetime, wartime when Turkey is not a belligerent state, wartime when Turkey is a belligerent state, and wartime when Turkey considers itself to be under threat.
Freedom of passage is thus guaranteed for all civilian ships during peacetime, while military ships are subject to certain limitations, such as: the obligation to notify the Turkish authorities 8 days (for the littoral states) and 15 days before transit, respectively, which in turn must inform the parties to the Convention; limitation of the type, number and tonnage of warships belonging to countries other than those bordering the Black Sea, the stationing of these ships is limited to 21 consecutive days; no access for aircraft carriers and submarines.
In situations of war and Turkey is neutral, no warships belonging to belligerent countries may pass through the Bosphorus and Dardanelles straits, except when returning to their port of departure. Also, in time of war, Turkey has the right to take decisions it deems appropriate and can authorise the transit of any vessel.

Montreux Convention implications for the region
The Convention was based on the idea that the riparian states should hold the key to access and the great Romanian diplomat Nicolae Titulescu, supported the move to give the key to the Black Sea to the Turks. This was accepted by the USSR and then the Russian Federation because it was in line with one of its most important strategic objectives, namely control of the Black Sea, as part of Russia’s policy of regaining international power and limiting the presence of NATO. In this way the Russian Federation holds the key to access to the region, limiting the presence of NATO and other countries that do not border the Black Sea, using Turkey, which apparently exercises control of access, in its own interest.
The war unleashed by the Russian Federation against Ukraine, the modern geostrategic realities represented by the Eastern flank of the Alliance, which includes the Black Sea region, the political, economic and cultural connections with the Eastern Mediterranean, the Middle East and the Southern Caucasus, all make the Black Sea part of an arc of instability that is and must be a concern for the countries of the region, NATO and the EU. Thus, the Black Sea region, which has traditionally been treated as a less important area, takes on new strategic significance.
Perhaps a first step in achieving regional stability could be to consider the status of the Black Sea, whether it remains a closed sea under the Montreux Convention or becomes an open sea under the Montego Bay Convention. The United Nations Convention on the Law of the Sea – UNCLOS (Montego Bay Convention), signed in 1982, defines the rights and responsibilities of nations with regard to the use of the world’s oceans and seas and is considered by experts to be “a comprehensive constitution for the world’s oceans and seas”. Article 35 of the Convention states that the legal regime of straits for which international conventions have been concluded will continue to be governed by these conventions. But even so, Turkey refused to sign the Montego Bay Convention.
Since 2004, with the accession of Romania and Bulgaria to the EU, the vision of changing the status of the Black Sea to an open sea has been emerging. In practice, EU Member States support the development of infrastructure projects in the Black Sea, and under these conditions they must have unrestricted access to these investments and facilities.
In 2004-2005, the European Union launched the Neighbourhood Policy, and in 2007, Romania contributed to the operationalisation of the Black Sea Synergy concept, which seeks to initiate an approach by coastal states to transform the Black Sea status into an open sea. All this effort culminated in the reluctance of Turkey, the Russian Federation and Bulgaria. The issue declined in relevance in 2008, after the Bucharest NATO summit, which did not offer Ukraine and Georgia consistent prospects of joining NATO. A few months after this summit, Russia attacked Georgia and Georgia lost control of South Ossetia and Abkhazia. In 2014, the Russian Federation significantly increased its relevance to the Black Sea, taking full control of the Crimean peninsula and the Kerch Strait. For these reasons practically the whole process was interrupted and the Black Sea remained a closed sea.
The invasion of Ukraine by the Russian Federation, which began in February 2022, has further highlighted the limitations of the Montreux Convention. As is known on 28 February 2022, Turkey activated the Montreux Convention, and closed the Black Sea straits to military vessels belonging to belligerent states in the conflict in Ukraine. This disrupted the logistical supply line for Russian troops in Syria, affected Russia’s ability to rotate forces in the Mediterranean, and prevented additional warships from entering the Black Sea. Even if Turkey’s activation of the Convention has apparently hurt the Russian Federation, the issues need to be examined more carefully.
With the closure of the Turkish Straits, Russia has found ways to provide logistical support for forces in Syria and for actions in Ukraine, using private companies or civilian ships. This involvement of commercial vessels in supplying combat actions violates the spirit of the Montreux Convention and the need to regulate these issues arises.
The Russian Federation has also violated the provisions of the Convention with regard to the transit of submarines. Article 12 stipulates that the coastal powers have the right to pass through the straits “for the purpose of returning to their home base, their submarines built or purchased outside this sea” and “submarines belonging to the said powers may also pass through the straits for repair in shipyards outside the Black Sea”. There is clearly no provision for the transit of submarines from the Black Sea to operate in the Mediterranean, which is common for the Russian Federation.
On the other hand, Turkey has used its right to interpret the Convention’s provisions on the transit of warships in Russia’s favour several times, and not only in the case of submarines. According to the Montreux Convention, the transit through straits of “surface warships other than aircraft carriers” is permitted under specified conditions. But Turkey has used its right to interpret the terms of the Convention in Russia’s favour several times politically in the past. One such case is the permission to pass for the aircraft carrier KIEV in 1976, with the USSR declaring this ship an anti-submarine cruiser. Another instance was when it allowed the Admiral Kuznetsov aircraft carrier to pass in 1981, this time the ship was declared a heavy carrier cruiser.
Another issue is the interpretation of access to the Sea and therefore the question here is the stationing period in the region for ships using access routes other than the Bosphorus and Dardanelles straits. In practice, the rivers and streams of the Black Sea basin are not covered by the Convention. Case in point: during the Second World War, Germany brought battleships to the Danube in support of the Romanian navy, which had the only fleet that could counter the USSR’s Black Sea fleet. Given these facts, it is possible that Romania could be back in the situation of the Second World War (allies unable to send ships to the Black Sea), in which case measures must be taken, both in terms of modernisation of the naval forces and the infrastructure for building and maintaining warships.
The prospect of changing the status of straits, through a revision of the Montreux Convention, has raised concerns about the further implications.
Russia has expressed its opposition to this project in various ways, as the current regime guarantees its status as a singular power in the Black Sea, protects its interests very well and imposes restrictions against a possible increased presence of warships from Black Sea countries or NATO vessels. Although there have been voices in Russia at times arguing for the need to amend the Convention, regarding the restriction of access of Black Sea state warships and their length of stay, the prevailing view in Moscow seems to be one that does not support a revision of the Convention.
On the other hand, several US officials have said that the rules of the Montreux Convention are outdated and can no longer respond to the security situation in the region. In this regard, it has been proposed to review the rules for entry of warships, the issues of the period of stay and the requirements for notifying Turkey of the passage of warships through straits.
Turkey also as we have presented has its own approach to the straits regime, promoting its own interests, showing everyone that it maintains control over the straits, even to the extent of unilaterally changing their regime. Thus Turkey indirectly amended the Montreux Convention on 20.07.2018, imposing new rules considered internal by Ankara, as follows: “Merchant vessels carrying warships must pass through Turkish straits under the status of warships” .
The construction of the Istanbul Canal will also automatically require an analysis of the provisions of the Convention, in a simple interpretation, the very creation of a new corridor, which is not foreseen in the Straits Convention, is somehow equivalent to a de facto revocation of the Convention.
To all these aspects we can add the fact that some of the countries bordering the Black Sea (Ukraine and Georgia) did not take part in the negotiations prior to the signing of the Convention, so there are more and more arguments supporting the need to initiate steps to amend the Montreux Convention to take account of the reality of the situation in the region.

The Montreux Convention was drafted when the Black Sea was under the control of the Soviet Union and Turkey, with the Soviet Union being superior, but now the situation in the region has changed. The Black Sea region is taking on a new economic and security importance, becoming increasingly militarised, unstable and contested, a region that urgently needs a new regional status quo in order to stabilise. There are also two trends in the region regarding control of the Black Sea.
For the Russian Federation, control of the Black Sea is one of Russia’s most important strategic objectives, in terms of borders with NATO and the EU, and is part of Russia’s policy of regaining international power and limiting NATO’s presence. This is also underlined in the Russian Federation’s Maritime Doctrine 2022, where the Black Sea is included in the Areas Important for Securing the National Interests of the Russian Federation.
On the other hand, Turkey’s tendencies to become a regional power are becoming more and more evident, and Turkey needs to act very diplomatically, or give in other areas, in order to avoid a collision of its interests, both with Russia and the states in the region, with the US/NATO/EU.
In fact the fragile balance on which the Convention was built, the control of the Soviet Union and Turkey, threatened to break down at the end of the Second World War, when tensions broke out between the USSR and Turkey, with the USSR pressuring Turkey to renegotiate the Montreux Convention so that the Soviets could share control of the Bosphorus and Dardanelles with Turkey. The “Turkish Straits Crisis of 1946”, when the Soviet Union increased its military presence in the Black Sea and pressured the Turkish government to agree to the establishment of military bases on Turkish territory. The situation triggered Turkey’s efforts to join NATO, which was achieved in 1952.
The Montreux Convention on the Regime of the Straits, while regulating passage through the Straits, also contains aspects of security concerns for countries bordering the Black Sea. A further interpretation of the provisions in favour of Russia may lead to the interests of the other littoral countries being affected, and even at some point the interests of Turkey. No one can guarantee that today’s good relations between Turkey and Russia will last forever and that we will not at some point see a repeat of the events of the “Turkish Straits Crisis of 1946”.
Romania, Ukraine, Georgia, even Bulgaria are interested in a greater US, NATO and EU presence in the Black Sea in order to achieve a stable security environment in the region, favourable to development, and in this case an action to revise the limitations that the Montreux Convention currently imposes on Black Sea vessels cannot be excluded.
Romania, on the other hand, must anticipate the possibility that the international agenda will discuss the need to analyse the situation of the Black Sea, whether it can remain a closed sea according to the Montreux Convention or become an open sea by applying the Montego Bay Convention. It is a most appropriate moment, given that the actions of the Russian Federation have led to a violation of the spirit of the Convention, and in recent years, with a not inconsiderable contribution from Romania and Romanian diplomacy, the region has received increasing attention on the agenda of the EU, NATO and the USA, materialised by multiple initiatives related to this region.

Cdor (rtg) Constantin Manea and Cdor Marian Moșneagu; Mica Valahie Publishing House – 2011; Law of the sea in peace and war: the legal regime of maritime zones and their impact on the conduct of actions in naval military conflicts, the forces and means used, their status and protection through international and domestic law rules;

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