The power and relevance of the Montreux Convention

The Montreux Convention Regarding the Regime of the Straits (July 20, 1936) is one of the most significant foreign policy achievements of the early Republican era. It brought peace and stability to Turkey and the Black Sea. Turkey achieved at Montreux what it could not fully secure in the 1923 Treaty of Lausanne. 

The signing of the Montreux Convention was influenced not only by Turkey's successful diplomacy but also by the balance of power at the time and the growing anxieties preceding World War II. From the 1930s onwards, Turkey drew attention to threats, particularly those originating from Italy. When Italy attacked Abyssinia (Ethiopia), the Western states saw once again how justified Turkey's concerns were. Beyond Italy, the rapid rearmament and expansionist ambitions of Germany, as well as Japan in the Far East, also contributed to the formation of a diplomatic climate favorable to Turkey. This situation paved the way for the adoption of a Straits regime that took Turkey's demands more into account, paid greater attention to Turkey's legitimate security concerns, and cleared the path for Turkey to militarize the Turkish Straits (the Bosphorus, the Sea of Marmara, and the Dardanelles). 

THE HISTORICAL IMPORTANCE OF THE TURKISH STRAITS 

Throughout history, the Turkish Straits have stood out strategically, both as a waterway and transit route, and in terms of their commercial and military dimensions. In this respect, they have been the subject of very sharp geopolitical, strategic, and diplomatic rivalries. For this reason, they have always been on the agenda through treaties, conventions, and legal regulations tailored to the conditions of the era. Naturally and inevitably, these legal arrangements have reflected the balance of power and the competition between great powers of the time. Before the Republic of Turkey, the Ottoman Empire also influenced these arrangements to the extent of its power. 

States bordering the Black Sea have always wanted to have more say and priority in the Straits compared to non-littoral states. They have strived to be privileged and to move freely when entering and exiting the Black Sea. They have tried to prevent, as much as possible, the passage of non-littoral states through the Straits and their entry into the Black Sea. In response to these efforts by Black Sea littoral states, the great powers have advocated for a regime that is as free as possible regarding passage through the Straits and have opposed restrictions. 

In the past, Great Britain, and subsequently the USA, have been known as states that desire the freest possible regime for passage through the Straits. Since the 1830s, in parallel with its growing power, the USA has advocated for the free passage of all vessels—whether commercial or military, and regardless of whether it is a time of war or peace—across all open seas. In contrast to these demands from Britain and the USA, another great power, Russia, has wanted the Straits to be as closed as possible to the commercial and military vessels of non-littoral states, and for passages to be restricted. 

After conquering Istanbul in 1453 during the reign of Fatih Sultan Mehmet, the Ottoman Empire established absolute sovereignty over the Straits. As it lost power, its sovereignty over the Straits eroded. With the 1841 London Straits Convention, a period of free passage began in the Straits. During the collapse period following its weakening, the Ottoman Empire lost its sovereignty over the Straits entirely after World War I. First with the Armistice of Mudros (October 30, 1918) and then with the Treaty of Sèvres (August 10, 1920), its sovereignty over the Straits was eliminated. According to the provisions of Sèvres, the Straits were made open to the passage of all vessels, and the Straits zone was placed under the control of a commission consisting of British, French, and Italian representatives. The Ottoman Empire could only provide opinions to the commission in an advisory capacity.  

THE USA'S OPPOSITION TO MONTREUX

It must be noted that the USA is at the forefront of countries that have been looking for opportunities for years to stretch, breach, and disable the Montreux Convention. In a world where the USA wants to permanently display its flag in the Black Sea, it should not be forgotten that the Black Sea has found peace and stability for years thanks to Montreux. If Montreux is breached, Russia-USA tension in the Black Sea will be inevitable. This situation would worry and put Turkey in a difficult position more than anyone else. It would strain Russia-Turkey relations. The NATO member countries in the Black Sea are Turkey, Romania, and Bulgaria. The significant support the USA provides to Ukraine and Georgia, which are not NATO members, is well known. Alongside the USA, the European Union also supports Ukraine and Georgia against Russia.

Montreux is not an ordinary convention to be ignored, neglected, or disregarded. It is a very important convention that secured the clear and absolute sovereignty of the Republic of Turkey over a very strategic section of its territory—which had been demilitarized and placed under international administration and control—by successfully utilizing the balance of power in the second half of the 1930s, just before World War II. In this respect, it completed Lausanne. How important and indispensable Montreux is has been seen during World War II, throughout the Cold War, after the Cold War, and finally, in the Russia-Ukraine War, which entered its 5th year in February 2026. If this convention, which is a work of Atatürk's diplomatic genius and which reinforced Turkey's reputation, prestige, and reliability before World War II, is opened to debate under pressure from the USA, it is certain that Russia will react very harshly.

The issue of ship traffic in the Straits, which is frequently brought up by those who open Montreux to debate, is not a valid argument. First, among the countries bordering the Black Sea, excluding Turkey and Russia, there is no major power or country with a high trade volume. Second, there has been a steady decline in ship traffic in the Straits in recent years. There are many reasons for this. Many factors can be listed, from the Russia-Ukraine war making pipelines more prominent in energy transport, to the West cutting off energy imports from Russia to a very large extent, leading to less need for tankers carrying oil and liquefied natural gas (LNG). In the coming years, as the weight of railways in freight transport between Europe and Asia increases further (China's Belt and Road Initiative envisions major investments in this regard), ship traffic in the Straits will decrease even more. Third, the Turkish Straits are not among the busiest tanker transit straits in the world. They are behind the Strait of Hormuz, the Strait of Malacca, the Suez Canal, and the Bab-el-Mandeb Strait. In other words, the Turkish Straits are known as a waterway with great strategic importance, but not such heavy ship traffic.  

DISCUSSIONS BEFORE MONTREUX AND THE GAINS OF MONTREUX 

Before negotiations began at Montreux in 1936, although Turkey and the Soviet Union had reached a consensus on the draft text to be presented to the conference, Moscow changed its mind during the negotiations. It tried to prevent the passage of warships of non-littoral states through the Turkish Straits. Moreover, it stated that the Turkish Straits should be defended jointly by Turkey and the Soviet Union. Faced with these proposals from the Soviet Union, Great Britain tended to defend the thesis that "Turkey's security is the priority," and followed a policy close to Turkey's theses, both to block the Soviet Union's demands and against the threat posed by the rising Germany in Europe. 

Ankara successfully utilized the major difference in attitude between Moscow and London under the conditions of the time and had the desired convention accepted by the signatory states. The Soviet Union, which signed Montreux in 1936, proposed to Turkey after a while to make a bilateral treaty between the two states in order to have more rights than the states that were parties to Montreux, by bringing up the proposals it could not get accepted during the Montreux negotiations once again. Ankara rejected this proposal from Moscow with a firm tone. While rejecting it, it stated that there was no need for another convention (whether bilateral or multilateral) while Montreux existed. It emphasized that taking a step in this direction would unnecessarily open Montreux to debate. 

It should be remembered that although Turkey's sovereignty in the Straits region was accepted in principle at Lausanne, there were some provisions that limited this sovereignty. The Straits region was demilitarized. Turkey would be able to keep about 12 thousand soldiers in Istanbul and its surroundings as a military force. Management and control regarding the regime of passage through the Straits were given to the authority of the International Straits Commission, whose president was Turkish. At Montreux, Turkey was freed from the restrictive regulations accepted at Lausanne regarding the Straits. Turkey issued a new Straits Regulation in 1994 and set important rules regarding free passage through the Straits. 

Montreux includes the principle of freedom of passage without any payment, although it foresees some differences for merchant vessels in times of peace and war. Regarding the passage of warships, it prohibits the passage of certain types of warships (aircraft carriers, submarines, and large warships above a certain size) of non-littoral states. Warships and auxiliary vessels of non-littoral states can pass into the Black Sea provided they comply with certain restrictions. They can stay in the Black Sea for a maximum of 21 days. The number and total weight of warships that the states in question can keep in the Black Sea during this period have been determined in detail. There are detailed provisions regarding the passage of warships such as wartime vs. peacetime, whether Turkey is a party to the war, and whether Turkey feels itself under an imminent threat of war. Montreux is very clear on these rules. There is not the slightest ambiguity, uncertainty, or situation open to interpretation. 

CONCLUSION

When considering the efforts of NATO, which has 32 members with the participation of Sweden and Finland, to strengthen its presence in Eastern Europe, the Balkans, and the Black Sea, the fact that the USA has given important tasks to Romania and Poland in this context, the increase in its bases in the region countries, the major military buildup it has carried out in Greece, and the attacks of the USA-Israel duo on Iran, the importance of Montreux is better understood. Because while the USA is not a littoral state to the Black Sea, the biggest obstacle in front of it as it tries to permanently be present in the Black Sea and breach the provisions of Montreux under the name of "NATO Naval Power" is Montreux. 

Today, from the war between Russia and Ukraine to the USA's efforts to permanently display its flag in the Black Sea by using NATO, despite so many problems in the region, if balance, stability, peace, and security could be established in the Black Sea, this situation is the work of the regime established at Montreux. Montreux is such a strong and solid convention that, besides preventing accidental, unintended, or fait accompli entry into a war, it has brought stability not only to Turkey and the states bordering the Black Sea but to the entire region. Therefore, opening Montreux to debate is opening Turkey's absolute and clear sovereignty over the Turkish Straits to debate.