180 Years of Power Struggle to Regulate the Access to the Black Sea

After Russian aggression towards Ukraine, Turkey closed off the Bosphorus and Dardanelles straits to all warships from any country. Turkey acquired its authority on the straits from the Montreux Convention which is the latest of the eight treaties governing the straits . Here is the brief history of how the agreements that govern the Straits evolved through conflicts and how it influences war in Ukraine.

The first multinational agreement dealing with the use of the Straits Bosporus and Dardanelles was the London Straits Convention which was signed in 1841 between the Great Powers of the Europe of the time—Russia, the United Kingdom, France, Austria, and Prussia. According to this agreement merchant ships of all nations gained for the first time free access through the straits breaking the absolute authority of the Ottomans. However, warships of all nations except the Ottoman Navy were not permitted to access into or out of the Black sea.

With this agreement, the great powers traded off their navy's access, for the imprisonment of the Russian fleet in the Black sea. On the other hand, this resolution was not detrimental to the Russian Empire because its ports and colonization efforts on the coasts of the northern Black sea were safe from foreign intrusion. This treaty is important because it was the first time that a European alliance imposed a sanction on Russia.

Later in 1856, the Treaty of Paris was signed to end the Crimean war between Russia and an alliance of the Ottoman Empire. This treaty added certain provisions to the London Straits Convention to close the Black Sea to all warships including the Russian and Ottoman.

Neutralization of the Black sea was a heavier sanction imposed on Russia weakening its local naval standing because Ottomans still could keep their naval forces and establish dockyards in the Straits, in Marmara, and Mediterranean seas.

The defeat was a warning signal for the Russian Empire. Its territorial gains in Crimea and Caucasus would be always in danger if these regions were not assimilated quickly. For these Russia employed all the tools from confiscation of lands to a repopulation of the region with loyal Christian subjects. As a result, millions of Tatars and Circassians had to quit their ancestral lands and moved to Ottoman lands.

In 1870, during the Franco‐Prussian War, Russia took the opportunity and unilaterally terminated the provisions related to the neutralization of the Black sea. Although it was a violation of international law, none of the Great Powers had the wish to solve the problem with another war. In 1871 the major powers Prussia, Great Britain, Austria, France, the Ottoman Empire, Italy, and Russia signed the Treaty of London.

With the new treaty, Russia once again gained freedom for its naval forces in the Black Sea. The western powers might also gain access to the Black Sea by requesting special permission from the Sultan.

In 1877, many Balkan countries were in revolt and Anatolia was hit by a famine causing widespread discontent in the heart of the Ottoman Empire. This was the opportunity for the Russian Empire to extend its influence. It also allowed recovering its territorial losses endured during the Crimean War of 1853–56. The Russo-Turkish War lasted for 10 months and was fought both in the Balkans and Caucasus. The Russian army reached the gates of Istanbul, only the pressure of Britain and sending a fleet of battleships to the Bosphorus could intimidate and stop Russia from entering the city.

With the 1878 Treaty of San Stefano Ottoman Empire lost a large territory in the Balkans, and also gave Armenian and Georgian territories in the Caucasus, including Ardahan, Artvin, Batum, and Kars to the Russian empire for the war reparations. However, this drastic power shift towards Russia caused concern for the Great Powers and they forced a revision at the Congress of Berlin and replaced the previous one with the Treaty of Berlin.

The Treaty of Berlin aimed to modify the borders of the freed states and limit the gains of the Russian Empires in the Balkans. It did not make a significant change for the Ottoman Empire or the regime of the straits.

Till the Treaty of Berlin major forces were content to lock the Russian navy in the Black sea. However, the Ottomans were too weak so they needed to enforce the straits. To be able to respond quickly to a threat to the Suez canal and the straits, Britain needed a port close by. The Ottomans provided this port by leasing out Cyprus to Britain.

Russia was well aware of the dominance of the British navy and closing the Black sea to all navies was safer in the short term.

Straits during the 20th century

After the defeat of the Central powers in WWI, each of them signed an armistice treaty with the allies. The armistice of Mundros was signed with the Ottomans in 1918. Accordingly, Allied powers occupied the Straits and the strategic points of Anatolia including Istanbul. The Straits were opened to all merchant ships and warships of all nations under the control of Allied powers.

In 1920 The Treaty of Sèvres replaced the armistice agreement. The treaty ceded large parts of the Ottoman territory to France, the United Kingdom, Greece, and Italy, as well as created large occupation zones within the Ottoman Empire.

Accordingly, an international Commission of the Straits was established to ensure free navigation through the Straits. In the Commission Ottomans, Greece, Bulgaria, and Romania each had a vote and each of the Allies' power had two votes. However, the treaty was never ratified. An independence movement in Anatolia had already begun. The Grand National Assembly, led by Mustafa Kemal Atatürk rejected the treaty and initiated the Turkish War of Independence.

Atatürk led the Turkish nationalists in the war of Independence and forced the Allies to sign the 1923 Treaty of Lausanne, which superseded the Treaty of Sèvres, ended the conflict, and saw the establishment of the Republic of Turkey.

At Lausanne representatives focused mostly on four issues regarding the Straits: freedom of passage, international guarantee, straits commission, and demilitarisation. The Allied powers looked for a liberal passage regime through the Straits. Soviet Russia, still having stability problems and feeling vulnerable, looked to block the passage of non-Black Sea warships. Turkey had too many problems to solve in Lausanne. While an Empire was dissolving a new state was forming, old and new accounts had to be settled. So Turkey could mainly focus on maintaining its sovereignty over the Straits, to ensure its safeguard and territorial integrity.

According to the new agreement, the Straits would be still supervised by the Straits Commission, but Turkey was to preside over it. Straits zones were demilitarised with the provision that Turkey maintains a garrison with a maximum strength of 12,000 soldiers in Istanbul.

The demilitarisation created a security risk for Turkey and the international guarantee provided to Turkey by the Treaty was vague in terms of defining the threat and the support to be provided. In addition, the decision-making process included members of the Union in addition to the guarantor states, which made it difficult to make quick decisions.

The merchant's vessels had complete freedom of navigation and passage through the Straits in times of peace and war. A foreign country without a coast to the black sea could send no more than three warships and each of which could not exceed 10.000 tons. Turkey could not take any measures to prohibit any passage of neutrals even if its security were in danger and warships affiliated with a conflict could also pass through the Straits as long as they kept peace in the Turkish seas or territories. During the time of war, while Turkey was belligerent, neutral warships were free to pass and this closure made Turkey vulnerable.

However, world politics had gotten increasingly tense. Germany, Italy, and Japan were building their land and naval forces. Turkey had developed peaceful relations and kept its neutrality. In 1936 Turkey called for negotiations for a new convention. The signatory states of the Lausanne Convention were ready to make changes. Soviet Russia supported the proposal hoping for better terms in securing its sensitive Black Sea coast and the industrial region of Ukraine.

The new Convention was signed in Montreux, Switzerland, on 20 July 1936 by France, England, Bulgaria, Japan, the Soviet Union, Turkey, Romania, and Yugoslavia. Turkey gained full control of the Straits and remilitarized the region.

In times of peace and in times of war while freedom of passage and navigation of merchant vessels of all nations is guaranteed, the passage is regulated by Turkey abolishing the International Straits Commission.

Non-Black Sea powers have to notify Turkey 15 days before the requested passage of warships, while Black Sea states require eight days. No more than nine foreign warships, with a total aggregate tonnage of 15,000 tons, may pass at any one time and no single ship heavier than 10,000 tonnes can pass. An aggregate tonnage of all non-Black Sea warships in the Black Sea can’t exceed 45,000 tons and they are permitted to stay in the Black Sea for at most 21 days. Passage of submarines also is not allowed with some exceptions for the regional forces. Any revision to these requires 3/4 majority of signatory countries and must include Turkey. Moreover, Turkey can close the straits to warships of belligerent parties in wartime or against a threat to its security.

Montreux convention in modern times

Montreux Convention is the latest of the eight treaties governing the straits. It is also the longest-lasting with 86 years. This is quite a big feat considering how fast the technology developed and world politics have changed. Nevertheless, the treaty shows its age.

In 1936 the 10,000 tons limit for the warships was meaningful because it prevented the access of foreign battleships and aircraft carriers to enter the Black sea. Today there are no battleships remaining in service or reserve with any navy worldwide. The choice of warships in modern warfare is lighter and more agile. For example, the Russian flagship Moskva which was sunk by Ukraine on the 14th of April weighed only 11,490 tons in a full load. The only limitation for aircraft carriers is their size. Today any ship which is weaponized with cruise missiles, even drones might fulfill many functions of an aircraft carrier.

It is also speculated that the Istanbul Canal which is planned to be built between the Black Sea and Marmara may circumvent the Montreux Convention. The Convention in theory aims to prevent competition and wars by limiting the presence of warships of rival naval powers in a small maritime area. Yet an alliance diverting their light but potent warships to the area can still form a strong force. So in practice, convention just reduces the risk of escalation by restraining navies from quickly moving to and from the Black Sea during an international crisis. On the other hand, probably the proponents of the Canal project vocalize this possibility just to counter the criticism of the rent-seeking aspect of the project. Otherwise, this type of circumvention would be strongly objected to on the grounds that the Convention regulates passage in and out of the Black Sea regardless of which waterway is used.

Montreux Convention and the Russian invasion of Ukraine

Today the Convention is on a trial. After the Russian invasion of Ukraine, Turkey decided to exercise its power to limit the passage of warships and refused Russian warships to enter the Black Sea, and prevented Russia from replacing its destroyed flagship. However, Russia may not be so unhappy because now has a valid reason not to risk another flagship being attacked by Ukraine. On the other hand, the countries which support Ukraine might also relax because they won't feel pressure to send any warships to the region.

Turkey acting according to the spirit of the convention prevents the aggressor from strengthening its forces and also prevents the conflict to spread. These daring times will show if the old treaty is still a potent tool for world safety and peace.

Izzet Enunlu