The Montreux Convention: The historic pact that has kept the Turkish Straits safe

Strict and objective implementation of the convention, coupled with diplomacy have worked well to keep the crucial passageway safe

Russian Navy's diesel-electric Kilo class submarine Rostov-on-Don sails through the Bosphorus Strait on the way to the Black Sea past the city Istanbul as Sultanahmet mosque (L) and Hagia Sophia mosque (R) are seen in the backround.
AFP
Russian Navy's diesel-electric Kilo class submarine Rostov-on-Don sails through the Bosphorus Strait on the way to the Black Sea past the city Istanbul as Sultanahmet mosque (L) and Hagia Sophia mosque (R) are seen in the backround.

The Montreux Convention: The historic pact that has kept the Turkish Straits safe

On any given day, at the southern entrance of the Strait of Istanbul, there are dozens of sea vessels of various sizes waiting for their turn to enter and sail through.

The same view is to be seen at the waiting areas — mooring basins as they are called — at the end of the Aegean Sea and Black Sea.

The waterway called the Turkish Straits, running between the Black Sea and the Aegean/Mediterranean, is made up of three sections: The Strait of Çanakkale (Dardanelles) at the Aegean/Mediterranean end (60km long), the Sea of Marmara in the middle (177 km long) and the Strait of Istanbul (Bosphorus) at the Black Sea end (27 km long).

The total length of the straits from one end to the other is 263km. A normal sized ship speeding at an avarage of 16 km per hour will sail from one end of the straits to the other in around 36 hours.

AFP
Russian warship BSF 142 Novotcherkassk sails through the Bosphorus strait off Istanbul to the eastern Mediterranean sea, on December 21, 2020.

When Ottoman power was at its height until the 18th century, navigation and passage through the straits were under its control.

As new power houses emerged — resulting in increased conflict with Russia, England and France, considerbly weakening the Ottoman Empire — passage through the straits was based on international agreements reached among these powers.

Russia’s gateway

The straits have always been important for Russia as a gateway — both in and out. They have been the historical route to the warm seas (Mediterranean Sea) and the route of Russia’s Black Sea Fleet.

Grain and other commodities from Black Sea coasts have been sent to their destinations through this gateway.

Technological advances and modern means of transportation may have had an effect but has not stripped the straits of their importance. When grain exports during the recent war in Ukraine stopped, global food security was negatively affected.

At the end of World War I in 1918, victorious allies occupied the Ottoman capital, Istanbul and the straits. In a war of independence and under the capable leadership of Mustafa Kemal Pasha (Atatürk, the founder of the modern Republic of Türkiye) the Turks defeated and pushed out the invaders.

The Lausanne Peace Treaty between Türkiye and the Allies was signed and the modern-day Republic of Türkiye was established. A seperate but integral part of this peace agreement was the Lausanne Convention Relating to the Regime of the Straits. It established the rules for navigation through the waterway.

What the signatories of the convention (USSR, Yugoslavia, Romania, Bulgaria, Türkiye, Greece, France, the United Kingdom and Japan) agreed on, however, was not the ideal outcome for Türkiye.

Its sovereignty was limited by demilitarisation of the straits and the establishment of a commission comprising members of signatory countries whose task was to control its implementation.

The Montreux Convention

In the 1930’s, Japan’s invasion of Manchuria and Italy’s military advance on Ethiopia, together with developments in Europe, created a new security environment which was very different from the time when the convention was signed.

Citing these changes and its concerns, Türkiye called for a conference. The response was positive and signatories met in Montreux, a Swiss resort town on Lake Geneva. After a month of intense negotiations, on 20 July 1936, they signed the Montreux Convention Regarding the Regime of the Straits.

Main elements of the revised convention (a total of 29 articles plus four annexes) were as follows:

To start with, full Turkish sovereignty was restored as the commission and demilitarisation efforts were halted.

The convention differentiated between two groups of states (Black Sea and non-Black Sea) basically in favour of the former but, at the same time, established a reasonable and applicable balance of interest between them.

The principle of the Montreux Convention is that in times of peace, merchant vessels should enjoy complete freedom of passage and navigation through the straits.

Exceptions were made under Articles 20 and 21 that stipulated that Türkiye could stop passage of all warships if it believed itself to be threatened with imminent war or encountered any belligerence.

Warships were subject to restrictions and limitations such as maximum aggregate tonnage, number of vessels and duration of stay in the Black Sea.

For example, Article 18 of the convention stipulates that in times of peace, the aggregate tonnage that non-Black Sea states may have in that sea would be limited to 30,000 tonnes. Also, vessels of war belonging to non-Black Sea states could not remain in the Black Sea for more than 21 days.

Meanwhile, aircraft carriers of any nation were banned from passing through. So were submarines, but with some exceptions for those belonging to the Black Sea states.

Prior notificaitons obligatory

Prior notifications for warships to Turkish authorities were obligatory. The notification period for Riparian States was set at eight days and for non-riparian states at 15 days.

Türkiye would ensure that all notifications complied with the convention. In cases they did not, Türkiye could ask for a correction and turn down the request for passage.

Since the signing of the convention in 1936, there have been major geopolitical events including World War II, the Cold War and the collapse of the Soviet Union. Throughout the turbulence of these major wars, the Black Sea has remained safe, and this is mainly attributed to the convention which remains intact.

In the 1930’s, Japan’s invasion of Manchuria and Italy’s military advance on Ethiopia, together with developments in Europe, created a new security environment which was very different from the time when the convention was signed.

Citing these changes and its concerns, Türkiye called for a conference. The response was positive and signatories met in Montreux, a Swiss resort town on Lake Geneva. After a month of intense negotiations, on 20 July 1936, they signed the Montreux Convention Regarding the Regime of the Straits.

Main elements of the revised convention (a total of 29 articles plus four annexes) were as follows: To start with, full Turkish sovereignty was restored as the commission and demilitarisation efforts were halted.

The convention differentiated between two groups of states (Black Sea and non-Black Sea) basically in favour of the former but, at the same time, established a reasonable and applicable balance of interest between them.

Complete freedom of passage

The principle of the Montreux Convention is that in times of peace, merchant vessels should enjoy complete freedom of passage and navigation through the straits.

Exceptions were made under Articles 20 and 21 that stipulated that Türkiye could stop passage of all warships if it believed itself to be threatened with imminent war or encountered any belligerence.

Warships were subject to restrictions and limitations such as maximum aggregate tonnage, number of vessels and duration of stay in the Black Sea.

For example, Article 18 of the convention stipulates that in times of peace, the aggregate tonnage that non-Black Sea states may have in that sea would be limited to 30,000 tonnes.

Also, vessels of war belonging to non-Black Sea states could not remain in the Black Sea for more than 21 days. Meanwhile, aircraft carriers of any nation were banned from passing through. So were submarines, but with some exceptions for those belonging to the Black Sea states.

Prior notifications for warships to Turkish authorities were obligatory. The notification period for Riparian States was set at eight days and for non-riparian states at 15 days. Türkiye would ensure that all notifications complied with the convention. In cases they did not, Türkiye could ask for a correction and turn down the request for passage.

Since the signing of the convention in 1936, there have been major geopolitical events including World War II, the Cold War and the collapse of the Soviet Union.

Throughout the turbulence of these major wars, the Black Sea has remained safe, and this is mainly attributed to the convention which remains intact.

Throughout the turbulence of major wars, the Black Sea has remained safe, and this is mainly attributed to the convention which remains intact.

Law of the Sea Convention 
 
The United Nations Convention on the Law of the Sea (UNCLOS) is an  international agreement that establishes a legal framework for all marine and maritime activities. It includes a clause on straits (Article 35c) which stipulates  that where a particular convention regulating passage through a particular strait exists, it prevails.  
 
This is the case for the Turkish Straits, where the Montreux Convention still stands.  
The war in Ukraine is yet another test of the convention. Within its provisions, Türkiye invoked Article 19 (in times of war, the straits should be closed to the passage of belligerent warships) and informed all Black Sea and non-Black Sea states of its decision.  
 
Some observers have argued that Türkiye's decision was largely symbolic and has not effected Russia's war effort. However, the important point is that the provisions of the convention were implemented without objections. 
   
Strict and objective implementation of the convention, coupled with diplomacy and politics of give and take have worked well. Passage through the straits is very pleasant — particularly the Strait of Istanbul, every inch of which is filled with history and natural beauty.  
 
Traffic accidents 
 
However, for maritime traffic, it can be perilious, and safety has become a major issue. 
 
Apart from dozens of towns and villages of various sizes which lie on the coastlines of the Turkish Straits, the city of Istanbul is located on the Bosphorus and the strait divides the city into two.  
 
There is very busy internal martime traffic in the Strait of Istanbul which includes shuttle boats, intercity ferries, fishing boats, tourist boats and personal vessels of all types and sizes.  
 
The population of Istanbul, according to 2021 official figures, is 15,840,000 and around 2.5 million commuters prefer to use the waterway. 
 
The straits — especially the Istanbul section — are famous for strong currents and reverse currents, sharp turns, sudden changes in weather conditions and, at times, low visibility.  
 
According to official figures, 403 major accidents have occured since 1948 in the Strait of Istanbul alone. Tankers carrying hazardous material including oil pose the riskiest threat. 
 
The biggest accidents were back in 1979 and in 1994 when oil tankers collided in the passage. A total of 70 seaman died and the oil-loaded ships burned for days. Sea traffic on the Strait of Istanbul came to a standstill and the city was paralysed.  
 
There was also heavy air and sea pollution as oil sank to the bottom of the sea and seriously damaged the marine environment — the effects of which are still being felt today. 
 
Historical-cultural heritage on the shores of the Strait of Istanbul is also threatened.  
On several instances, vessels passing through have crushed into hundreds of years old seaside mansions (Yalı in Turkish) and other monumental structures on the shores. One such structure to suffer recently was Yalı of Amcazade Hüseyin Paşa, the oldest in Istanbul, built in 1699.  
 
Increase in traffic 
 
The number of merchant vessels passing through the straits stood at a daily avarage of 17 in 1936,  whereas, in 2021, the number of vessels which passed through the straits of Istanbul and Çanakkale were 38,551 and 43,342 respectively. 
 
It is not only the number of vessels that count, but also their gross tonnage and what they carry. In 2021, the total gross tonnage of vessels which passed through was 631,920,375.  
 

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Picture taken from the Galata Tower in Istanbul, 02 June 2004 shows the Galata Bridge and maritime traffic along the Bosphorous.

The number of vessels longer than 200 meters which passed through Istanbul Strait was 5,306. For Canakkale Strait, the number was 7,855. One can only imagine the difficulty of a 200-meter long vessel passing through a strait whose narrowest point is only half a mile wide, making navigation a challenge. 
 
A look at other waterways makes the burden on the Turkish Straits even more clear. According to the Suez Canal Authority, the average number of ships which passed through the Suez Canal between 2011-2019 was 17,520. In 2021, the number of ships passing through was 20,694.  
 
For the Panama Canal, the number of ships which pass through annually are around 14,000.   
 
As for warships, in  2021, a total of 190 vessels passed through the Turkish Straits, among which 119 belonged to Black Sea states, 107 were Russian and 12 were from other Black Sea states.  
 
The number of merchant vessels which pass through the straits may have stabilised or even decreased in recent years due to various reasons, including increases in prices in the shipping sector, alternative means of transportation, energy pipelines and bigger ships.  
 
But despite the drop in vessel numbers, total gross tonnage and the number of vessels longer than 200 meters have increased.  
 
In any case, the more than 81,000 vessels (merchant and war) passing through the Istanbul Strait and the Çanakkale Strait continue to constitute an enormous load and a serious challenge, that will only intensify in the years to come.   
 
Effective regulations  

The principle of free passage does not mean unregulated passage. Navigational safety is an integral part of the Montreux Convention and based on this, Türkiye developed "Turkish Straits Regulations" in 1994.

It also introduced traffic seperation schemes. These are instruments used to regulate traffic in busy, confined waterways to ensure safety of navigation. 

In light of lessons learned, these regulations were reviewed in 1998 and in 2019.  

Some examples of these regulations are: ships have to keep a certain distance between them while passing through the straits, they can only pass at certain hours, and there can only be a certain number of ships in the passageway at a given time.  

These regulations which have been registered with International Maritime Organisation (IMO) have proved effective as there has been a sharp drop in the number of accidents since their implementation.  

Passage through the straits is free of charge except for services such as lighthouse, life saving and health inspection. Piloting is voluntary and, if used, there is a charge. The charges are updated at certain intervals in accordance with the convention.  

However, the straits should not be considered a source of major revenue. The average annual revenue is around $40 million and is expected to go up to around $200 million after the last update that went into effect on 7 October 2022. 

 

The straits should not be considered a source of major revenue. The average annual revenue is around $40 million, compared to the Suez Canal's $6.3 billion.

In comparison, the revenue from the Suez Canal is among the major sources of  revenue for Egypt. The Suez Canal Authority announced its annual revenue of $6.3 billion in 2021. In the case of the Panama Canal on the other side of the world, revenue stood at around $3.9 billion in 2021.  

Canal Istanbul 

President Recep Tayyip Erdoğan likes coming up with mega projects.  His "mega mega project" or crown jewel is Canal Istanbul which he first announced in 2011. 

The project will see a canal built in the Western Thrace on the outskirts of Istanbul. The canal will allow ships to enter the 45km-long man-made canal from the Black Sea and sail into the Marmara Sea, thus, by-passing the Bosphorus.  

The idea here is that it will ease the burden on Istanbul and protect it from risks of intense maritime traffic. Additionally, there will be a charge for passage.  

Its opponents regard the project as politically, financially and environmentally unfeasible and unnecessary. They even claim that what lies at the core of this project is profit based on land speculation. 

Then there is the debate as to how this project would fit into the Montreux Convention and whether convention provisions would apply.  

The official government view is that as long as it is not obligatory for merchant ships to go through Canal Istanbul, Montreux will not be affected.

In other words, the convention will be applicable for ships passing through the straits but Canal Istanbul will be an internal waterway and all passages will be subject to Turkish domestic laws.  

Erdoğan is determined to move this project forward, but opposition leaders are determined to kill this project should they win in upcoming elections slated for spring of 2023. 

 

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