The Montreux Convention Regarding The Regime Of The Straits: A Turkish Perspective

The Montreux Convention regarding the regime of the Turkish Straits was signed on 20 July 1936 in Montreux. With this convention, the Republic of Turkey managed to end the issue of Straits, which was resolved temporarily with the Treaty of Lausanne, so as to protect its own safety and interests.

Considering the historical developments, Turkey had to allow the Straits as a gun-free zone to be administered by the Straits Commission under the Treaty of Lausanne. This situation which threatened Turkey’s absolute sovereignty and security over its territory had to be corrected due to the increasing political tensions in Europe in the late 1930s. The Montreux Convention was the result of the political and diplomatic efforts that were made in this direction.

Through this convention that was signed by Australia, Bulgaria, Great Britain, Japan, France, Romania, the Soviet Union, Yugoslavia, Greece and Turkey, Turkey’s limited rights were given back. Turkey gained sovereignty over the Straits Zone. The USA was also invited to the conference that was held before the convention. However, the Washington Government preferred not to participate and thus couldn’t become a signatory.

500px-Turkish_Strait_disambig.svg

Northwestern Turkey is divided by a complex waterway that connects the Black Sea to the Sea of Marmara and the Aegean Sea. The channel passing between the Black Sea and the Sea of Marmara is named the İstanbul Boğazı, more commonly called the Bosporus. Istanbul, the largest city of Turkey is positioned at the south end of the Bosporus. The Sea of Marmara is connected to the Aegean Sea by a channel called the Çanakkale Boğazı, also known as the Dardanelles. The Turkish Straits, comprising the Strait of Canakkale, the Strait of Istanbul and the Sea of Marmara, are unique in many respects. The very narrow and winding shape of the strait is more akin to that of the river. It is an established fact that the Turkish Straits are one of the most hazardous, crowded, difficult and potentially dangerous waterways in the world for marines. All the dangers and obstacles characteristic of narrow waterways are present and acute in this critical sea lane.

The Montreux Convention guarantees free passage of civilian merchant ships without any restriction through the Dardanelles, the Sea of Marmara and the Bosporus in peacetime. Therefore, the adoption of the Turkish Straits Vessel Traffic Services System, which was put into practice by Turkey when the number and tonnages of vessels passing through the straits increased dramatically, became possible after serious diplomatic negotiations between the signatories of the Montreux Convention.

Six out of 29 articles of the Montreux Convention were related to the civilian merchant ships while 16 of them were related to warships and aircraft. Provisions regarding the passing of warships through the Straits vary depending on whether these ships belong to a country with or without a shore on the Black Sea. Also, these provisions vary depending on whether Turkey is belligerent or sees itself under a close war threat.

The definition of “ton” in the Montreux Convention, unless otherwise specified, refers to the long ton, which is equal to 1016 kg (2240 pounds) instead of the metric ton that is equal to 1000 kg.

Passage of warships
The Black Sea riparian countries have the right to transit their warships and submarines through the Straits without any tonnage restriction provided that Turkey is notified eight days prior to the transit passage through diplomatic channels

Ships that have a greater tonnage than 15.000 tons may pass through the Straits one by one and be escorted by not more than two destroyers.

Only submarines belonging to riparian states can pass on the surface and singly through the Turkish Straits, for the purpose of rejoining their base in the Black Sea for the first time after their construction or purchase, or for the purpose of repair in dockyards outside the Black Sea.

There are severe restrictions in terms of type, number and tonnage for the transit through the Straits of warships that belong to the non-Black Sea countries. These non-riparian countries are required to notify Turkey 15 days, prior to the transit through diplomatic channels.

The total number and the maximum aggregate tonnage of all foreign naval forces which may be in course of passage through the Turkish Straits are limited to 9 and 15.000 tons respectively. The maximum aggregate tonnage that non-riparian States may have in the Black Sea is 45.000 tons. In this regard, the maximum aggregate tonnage of the vessels of war that one non-riparian State may have in the Black Sea is 30.000 tons. The non-riparian states cannot keep their warships for more than 21 days in the Black Sea.

Due to its date of signing, the Montreux Convention does not have a clear statement with regard to nuclear-powered vessels. In fact, in the convention, there is not a statement with regard to the engine types of the ships that will pass through the Straits. In theory, the transit of a nuclear-powered ship through the Straits is not restricted. However, today nuclear-powered warships are either submarines or aircraft carriers with huge tonnage.

The transit of a submarine or an aircraft carrier belonging to a country without a shore on the Black Sea is not possible. Therefore, a nuclear-powered warship has not passed through the Straits officially so far.

The only type of warship that is exclusively banned from passage through the Turkish Straits is the aircraft carrier.

Turkish Straits during a War or Crisis
In the time of war Turkey not being belligerent, the peacetime rules apply for the warships belonging to non-belligerent parties. Warships belonging to the waring states cannot pass through the Turkish Straits, The only exception of this is that if the warships belonging to belligerent countries with or without a shore on the Black Sea have already left the ports that they are affiliated to before the war, they have the right to transit in order to return to their ports.

In time of war, Turkey being belligerent, the passage of warships is entirely left to the discretion of the Turkish Government.

The Southern enterance of the Bosphorus. The old city, The Golden Horn are visible at the bottom. At far left the first Bosphorus Bridge can be seen.

Similarly, if Turkey considers itself to be threatened with imminent danger of war, the transit of warships belonging to foreign countries through the Straits is left to the discretion of the Turkish Government.

By means of this authority, Turkey can prohibit the transit of warships belonging to the countries that cause Turkey to consider itself to be threatened with the danger of war while it can allow the transit of warships belonging to countries that do not cause that such situation.

With the Montreux Convention regarding the regime of the straits, which we have tried to summarize above, the number, type and size of the warships that can reach the Black Sea have been restricted. These restrictions increased the security of the riparian states. However, the same restrictions prevent the desire of countries with powerful naval forces to be present and cruise in all seas all around the world.

Turkey has been trying to implement the Montreux Convention with great precision since 1936. Therefore, occasionally Turkey is exposed to criticism from countries both with and without a shore on the Black Sea. The first big test of the Montreux Convention was, no doubt, the Second World War. Turkey closed the Straits to the warships of the belligerent countries during this war in which Turkey remained neutral. This situation served the purpose of the Soviet Union since the transit of German submarines and warships through the Straits was prevented. Axis countries couldn’t bring new warships to the Black Sea except for those that were already in the Black Sea before the war. Submarines were transferred in pieces by land or through the Danube River so that they could be assembled in Romania.

This however also prevented the military aid convoys coming from its allies, the UK and the USA, to pass through the Straits. Therefore, much of the military aid from the USA and UK had to be carried to Russia either over Iran or over the North Pole route.

Montreux During The Cold War
During the Cold War, Turkey was exposed to criticism both from the Soviet Union and the NATO allies from time to time due to its way of implementation of the Montreux Convention.

In 1976 when Turkey allowed the warship Kiev to pass through the Turkish Straits, many NATO allies including the USA protested Turkey. The Kiev, constructed in the Nikolayev Shipyard in the Black Sea in 1972 was considered as the first aircraft carrier constructed in the Soviet Union. However, having been quite aware of the fact that violating the Montreux Convention would not be good for its own benefit, the USSR classified Kiev as a heavy anti-submarine cruiser.

The Montreux Convention, defines aircraft carriers as surface warships, regardless of their tonnage, designed and constructed mainly to carry aircraft and enable their operation of them. If a warship was not designed or constructed with the sole purpose of carrying and operating aircraft, is not considered as an aircraft carrier even if the ship has a suitable deck for the aircraft’s take-off and landing.

Kiev and her sister ships had long-range anti-ship and air defence missiles as well as anti-submarine warfare rockets. Thus, the Soviet Union was able to classify these ships as heavy anti-submarine cruisers. All the ships of this class, Kiev, Minsk, Novorossiysk and Baku passed frequently both northbound and southbound through the Turkish Straits while they were commissioned.

This is not a carrier. Admiral Flota Sovetskogo Soyuza Kuznetsov passing through Bosphorus

A similar crisis happened in 1991 when Admiral Flota Sovetskogo Soyuza Kuznetsov, still commissioned in the Russian Naval Forces, passed through the Turkish Straits. Although this ship looked like a classical aircraft carrier in terms of its structure, the Soviet Union classified it as a heavy cruiser due to weapon systems deployed onboard. Again some NATO members put serious pressure on Turkey not to allow this ship to pass through the Straits, but they didn’t succeed in this effort.

Unlike Kiev class ships, the Admiral Flota Sovetskogo Soyuza Kuznetsov didn’t pass through the Straits ever, after leaving the Black Sea in December 1991.

Montreux in the New World
After the terrorist attacks on 11 September 2001, the U.S. Government requested help from the NATO countries within the scope of Article 5 of the NATO Treaty. According to this article, an armed attack against a NATO country is considered an attack against all of the NATO countries.

In this context, on 26 October 2001 Operation Active Endeavour (OAE) the first anti-terror operation of NATO was launched. The operation began with the patrols of the warships belonging to NATO countries in the Eastern Mediterranean was later on expanded so as to search the suspicious ships and their loads.

Upon the success of the OAE in the Eastern Mediterranean, the operation was expanded to the whole Mediterranean in March 2004. At the same time, the Turkish Naval Forces launched Operation Black Sea Harmony (OBSH). The purpose of OBSH was to ensure security in the Black Sea, create situational awareness and control suspicious merchant ships. The recognized maritime picture obtained within the scope of the operation, which is still ongoing, is shared with the NATO authorities and headquarters.

Initially, only units of the Turkish Naval Forces participated in OBSH. Later Turkey invited all littoral countries in the Black Sea to participate in the operation that was launched with its own initiative, and Romania, Russia and Ukraine responded positively to this invitation. The most important effect of the OBSH was that all the pressure exerted to modify the Montreux Convention and expand the OAE into the Black Sea was neutralised. Otherwise, if OAE was extended into the Black Sea, warships belonging to non-riparian NATO countries would be regularly present in the Black Sea and successful implementation of the Montreux Convention would be jeopardised.

After the Russian invasion of Georgia in 2008, the Montreux Convention was widely discussed again. Turkey received a lot of flak for refusing the transit of the hospital ship USNS Comfort. The USA wanted to dispatch the ship with a 69.552 displacement to Georgia to show solidarity and provide aid. However the article of the Montreux Convention is very clear about the sizes of the ships to be sent for humanitarian reasons: “In the event that one or more countries without a shore on the Black Sea desire to send naval forces into the Black Sea, for a humanitarian purpose, the said forces cannot exceed 8.000 tons.” The neo-conservative U.S. government was not happy with this decision.

The Russian annexation of Crimea in 2014, and NATO’s anti-ballistic missile defence system were the most recent times when Ankara faced pressure on how it implemented the Montreux Convention in dealing with foreign navies’ requests for transit to and from the BlackSea.

What Now?
Turkey will face challenges regarding the implementation of the Montreux Convention, especially after Ukraine calls on Turkey to close its airspace and the Black Sea access to Russian vessels on 24 February 2022. The Russian invasion of Ukraine showed that Russia indeed is the major challenge in terms of the security and stability of Europe in general and the Black Sea region specifically.

Turkey created a security architecture in the Black Sea with the riparian states. This apparatus keep the security in the region and keep the warships of the non-riparian states out. This architecture worked when the Russian Black Sea Fleet was weak and the NATO’s enlargement toward the east was slow. It even survived the Russian attack on Georgia in 2008. However, in 2014, Russia’s annexation of Crimea meant the collapse of the regional security architecture.

In recent years, Russia displayed its discontent towards the existence of foreign warships in the Black Sea by shadowing them constantly and flying military planes aggressively low and close to these vessels of war. On the other hand, NATO is trying to find ways to keep more warships of non-riparian States in the Black Sea and keep them longer.

When determining ways to bring stability to the Black Sea region and to answer the security challenges caused by Russian aggression it is important to remember that the Montreux Convention is simply far more than just a treaty that regulates the passage of commercial and naval ships through the Turkish Straits.

The Montreux Convention completes the Treaty of Lausanne, allowing Turkey to have full and absolute sovereignty and security over its territory. Therefore it is vital for Turkey to keep the convention alive and relevant.

Note: I have first written this text in 2014 for the Turkish online defence magazine C4 Defence in Turkish. It was published in the March 2014 Issue. Since then it was also published on web site Second Line of Defense. I have changed the original text in light of the recent Russian attack on Ukraine.

FS Auvergne Passed Southbound Through Istanbul

The French warship FS Auvergne made her southbound transit through Istanbul this morning and left the Black Sea.

Her northbound passage was on 13 December 2021. During her deployment to the Black Sea, the ship visited Constanta, Romania and Odessa, Ukraine.

This was her first Black Sea deployment.


Serial Production Line Qualification Test Of Atmaca Missile

Turkish Navy conducted another live firing of Atmaca anti-ship missile on 18th June 2021.

The test was conducted again at the live-fire exercise area off the coast of the Black Sea town Sinop. The last of the Ada class corvettes, TCG Kınalıada had the honour to do testing. At the receiving end of the missile was this time not a target barge but decommissioned salvage and submarine rescue ship Işın.

The missile used was, assumed to be the first missile from the serial production line. Here are some screen captures from the videos published from the test.


This photo shows Atmaca right before impacting the target ship. The missile is capable of flying very low, making it difficult to differentiate from clutter and engage.

The missile hit the target amidships in the area marked in red. The hole is just above the water level.

The initial videos shared from the test ended when the missile hit the ex Işın, leaving enthusiasts wondering about the size and location of the damage. However, videos showing the damage submerged shortly after.

There is even a video showing the damage the missile has created inside ex Işın. This means that the ship did not sink immediately after the impact. There was enough time for some to go onboard and survey the damage from inside. That is reasonable as ironically it is more difficult to sink an empty ship than one in active service. The striped down hulls have nothing on them. No fuel, no ammunition no warheads or any incendiary material which may create secondary explosions and spread the fire.

When the serial production starts the Atmaca missile will replace the Boenig Harpoon missiles on Turkish warships probably on a one-to-one basis. This will need some changes in combat management systems to incorporate the new missile into existing software. The Ada class corvettes are the most likely candidates as the Genesis CMS is made by Havelsan. Thus this CMS is the easiest one to add the Atmaca. The next ships equipped with Atmaca might be the Barbaros class frigates that will receive the mid-life upgrade program or the Istanbul class frigates whichever comes first. Both classes of ships will again locally developed CMS making it very easy to add the new missile.

Ever since the long-range anti-ship missiles replaced the guns as the main offensive weapons, having total control and command on every aspect of this weapon has become vitally important for the war-fighter. By replacing the foreign missiles with local ones Turkish Navy will be able to trust that its punch will find its mark.

Turkish Navy Takes The Helm Of SNMCMG-2

The ships of the SNMCMG-2 in one shot. From far to near: TCG Ayvalık, ESPS Tajo, and the flagship TCG Sokullu Mehmet Paşa. The hand-over ceremony took in the small harbor in Tuzla, İstanbul at the premises of the Naval Academy where the flagship has its home port. 

Turkish Navy took the helm of the NATO Mine Countermeasures Group Two with a ceremony held on 19 February 2021 in Istanbul.

SNMCMG2 will be commanded by Turkey for the fifth time since the inception of the group. Between 20 February-16 April 2021, the group will participate in mine warfare exercises in Greece, Italy, and Romania. MCM vessels from Bulgaria, Greece, Italy, Romania, Spain, and Turkey will take part in SNMCMG2 at different periods.

Captain Yusuf Karagulle, the new Commander of SNMCMG2, said that during his term the task force will operate in the Black Sea and the Mediterranean in order to enhance NATO’s solidarity and readiness in these regions. Besides NATO and non-NATO port visits, will participate in three exercises.

There is one odd thing about the whole thing, I couldn’t quite put my finger on: The duration of the command. Usually, the command of a NATO task force is rotated annually or semi-annually at best. This time Turkey is taking the command for 56 days. Not even two full months. Why was it necessary to take the helm for such a short time and what is the reason behind this unusual short duration of the command.

It was 2016 when the last time when Turkish Navy was in Command of SNMCMG-2.

What Is The Blue Homeland?

Below is written by retired Admiral Cem Gürdeniz. The original text appeared at uwidata.com and is used here with permission. You can read the whole text here.

The Blue Homeland is a concept, a symbol, and also a doctrine. 

As a concept, its scope consists of all maritime jurisdiction zones (inland waters, territorial waters, continental shelf, exclusive economic zone), declared or undeclared, as well as rivers and lakes. The Blue Homeland, in an exact sense, is an extension at sea and seabed of our homeland located between 26-45 East longitudes and 36-42 North latitudes. The Blue Homeland is the name of our zone of interest and jurisdiction over salty and fresh waters located between 25-45 East longitudes and 33-43 North latitudes.

As a symbol, it designates Turkey’s maritimization as its grand strategic goal for the state and its people in the 21st century. It symbolizes redirection of land-based mentality in Turkey to seas and thereby to achieve maritimization of its people.

As a doctrine, it’s a roadmap aimed to protect rights and interests in the seas surrounding Anatolia as well as seas and oceans beyond its periphery. Thereby, with their unique features, maritime principles and thoughts would be transformed into an illuminating roadmap and define our future on the axis of geopolitical zones of influence and defense. This concept could present new opportunities within the global process at a time of transition from unipolarity to multipolarity, from Atlantic age to Asian age, to strengthen Turkey’s geopolitical control over the Eastern Mediterranean, the Black Sea, and the Straits. It may open unprecedented windows for change in Turkey’s dossier of global, continental, and regional relations. Naturally, this doctrine necessitates Turkey’s legitimacy with international law to dominate maritime zones as well as capabilities and volition to trigger events over political, diplomatic, military, and economic dimensions.

Ivan Khurs Deployed to the Mediterranean

Yesterday, Ivan Khurs a Project 18280 class intelligence-gathering warship of Russian Black Sea Fleet transited through Istanbul.

This is the start of her first Mediterranean deployment. She was launched in 2017 and joined the Russian Black Sea Fleet in 2018. Her inaugural voyage to her base in Sevastopol was in December 2018. She has passed through Istanbul ob 27th December 2018 after sunset. So we are not able to see much of her.

Since her recent deployment happened in broad daylight we are able to observer Ivan Khurs.

Below are 3 photos of the various antennas onboard Ivan Khurs.

TCG Kınalıada Joins Turkish Navy

TCG Kınalıada in Istanbul Naval Shipyard. This photo was taken on May 2019 by Gökhan Karakaş.

The fourth and the final Ada class Corvette TCG Kınalıada was commissioned to the Turkish Navy on 29th September 2019.

TCG Kınalıada has entered into service 8 years after the first ship of the class was commissioned. Her entry also means the completion of Milgem class corvette production for the Turkish Navy.

On the outside, TCG Kınalıada may very much look like the first ship TCG Heybeliada, but she incorporates significant improvements reflecting the advance of the Turkish defense industry during the last decade:

  1. TCG Kınalıada is the first ship ever to be fitted with the indigenous Atmaca anti-ship missile. The corvette is expected to conduct a live firing of the missile in November. When officially commissioned Atmaca will be fitted back to the existing warships in the inventory.
  2. TCG Kınalıada and TCG Burgazada are fitted with Aselsan Seaeye-Ahtapot electro-optic sensor on the aft mast while the previous ships use Aselflir 300. Aselflir 300 was originally designed for airborne platforms and was installed without much modification for a service on a warship. Thus the meantime between regular maintenance is quite short for a maritime system and the whole sensor must be taken down for the maintenance. These shortcomings are rectified in Seaeye-Ahtapot. It has a better tracking range and resolution.
  3. TCG Kınalıada and TCG Burgazada have Aselsan made Hızır countermeasure system for torpedo attacks.  The system consists of two decoy launchers on both sides of the funnel and one towed array and decoy. Though the system is very similar to a torpedo countermeasure system SeaSentor manufactured by Ultra, used the other ships. The logistics of a locally constructed system is preferred by the end-user.
  4. Another important change inside TCG Kınalıada is the new Genesis Advent combat management system with network-enabled capability. This new CMS has native data link capability and can manage Link 11,16 and 22 at the same time. It increases situational awareness. When ships are installed with Genesis Advent they will be able not only to see and share the same tactical picture but also to control and train each other’s sensors and weapon systems.

When I was watching the commissioning ceremony, I couldn’t stop thinking about, what would have happened, if the tender for the construction of 6 Milgem class, won by RMK Marine Shipyard had not been canceled back in 2013. Since the cancelation of the project happened before the completion of the contract negotiation thus we will never know the planned delivery dates. But surely we would have 2 to 3 more Milgem type corvettes in inventory as we do have now.

Even the best ship cannot be in two places at the same time.  And we need more warships now both to rejuvenate our aging fleet and to protect our interest in the blue homeland.

First Steel Cut For Pakistan Navy Milgem Project Ship


Pakistan Navy Chief OF Staff Admiral Zafar Mahmood Abbasi and the President of the Turkish Republic, Recep Tayyip Erdoğan jointly cut the first steel of the first Milgem class warship for Pakistan. The ceremony was held on 29th September 2019 in Istanbul Naval Shipyard.

In July 2018, a contract was signed between Military Factory and Shipyard Management Corporation (ASFAT) of Turkey and the Pakistani National Defense Ministry Ammunition Production and Karachi Shipyard for the construction of four Milgem class warships. The construction of the first ship will take 54 months and she is expected to be launched in 2012 and delivered to Pakistan Navy in 2023. The remaining ships will follow her in 6-month intervals. The last ship will be handed over in 2025.

The contract has also provisions for transfer of design rights and construction know-how from Turkey to Pakistan.

The first batch of two ships will be constructed in Istanbul Naval Shipyard while the remaining two in Karachi Shipyard & Engineering Works.

The exact configuration of the Pakistan Milgem Class ships has not made public. During the Aman Naval Exercise held in February 2019, Admiral Abbasi said that Pakistan ships will be fitted with a 16-Cell VLS behind the main gun for Chinese made medium-range air defense missiles probably LY-80/HHQ-16 variant.

The main offensive weapons of the Pakistan ship could be either Chinese C-802 or local Harbah ASCMs. A CGI image used during the ceremony shows Turkish Aselsan built Gökdeniz close-in weapon system on the Pakistan ship in place of the RAM missile launcher of the Turkish ships.

Turkish Naval Forces Day Commemorated With A Sail Parade

The 27th September, the anniversary of the Battle of Preveza, is celebrated as the Turkish Naval Forces Day.

On 27th September 1538, a naval battle for the supremacy in the Mediterranean was fought between the Ottoman Navy commandeered by Barbaros Hayrettin Pasa and the fleet of a Christian alliance assembled by Pope Paul III and commandeered by Andrea Doria. With the victory at Preveza and the subsequent victory in the Battle of Djerba in 1560, the Ottoman Empire successfully repulsed the efforts of Venice and Spain, the two principal Mediterranean powers, to stop the Turkish drive to control the Mediterranean.

To commemorate the day Turkish Naval Forces organized a sail parade through Istanbul. 8 warships and two special forces RHIB’s took part in the ceremony. All these ships minus TYCG Sancaktar are open for public on Friday afternoon and on Saturday in Istanbul. In all Turkey, 45 ships will be open for public to visit.

F-247 TCG Kemalreis the flagship of the Turkish Navy.

F-246 TCG Salihreis. She too has extra space and equipment to act as a flagship.

F-241 TCG Turgutreis. First-generation of MEKO 200 type frigates in service.

F-512 TCG Büyükada. The second Ada (Milgem) class corvette. She was launched 8 years ago on this day and commissioned 6 years ago again on this day.

F-511 TCG Heybeliada. The first indigenous warship constructed in Turkey. She was commissioned 8 years ago on this day.

L-403 TCG Sancaktar. The newest landing ship in inventory. She has extensive command and control facilities for land operations. 

P-335 TCG Atak. 

P-337 TCG İmbat. Both TCG Atak and TCG İmbat are the last generation of fast attack craft in the Turkish Naval Forces.

Albanian Patrol Vessels Visit Izmir

Albanian offshore patrol vessels ALS Oriku (left) and ALS Butrinti in İzmir Port in mid-July.

In mid-July, ALS Oriku arrived in İzmir, Turkey to replace her sister ALS Butrinti and.

The 42,8 meter long, boats have 260 tons of displacement. Their 20mm remotely controlled gun turrets were installed in 2018.

ALS Butrinti has patrolled on behalf of NATO Standing NATO Maritime Group Two Task Unit 01 since January 2018. Her replacement ALS Oriku will be deployed in the region until the end of the year.

While the boats are swapped in 6-month periods, the crews only serve for about 3 months. The 21-strong crew of ALS Oriku represents the 12. Albanian Contingent.

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