One NATO Ally Can Easily Block Russian Warships from Joining the Battle

[marmar]

(Slate) On Sunday, Turkish leaders labeled Russian’s invasion of Ukraine a war, a rhetorical shift that sets the stage for Turkey limiting warships transiting the Turkish Straits and entering the Black Sea. Speaking on CNN Turk, Turkish Foreign Minister Mevlüt Çavuşoğlu stated that “the situation in Ukraine has transformed into a war” and Turkey “will implement all articles of Montreux transparently.” Çavuşoğlu was referencing the 1936 Montreux Convention, an international agreement that governs the transit of all vessels and airplanes through the Turkish Straits, a strategic chokepoint that links the Black Sea with the Mediterranean Sea. As the Russia-Ukraine conflict rages, the Montreux Convention has taken on increased importance as a potential regulator of warship traffic into the conflict zone. If Turkey formally invokes Montreux’s wartime provisions, Russian warships will generally be prohibited from entering the Black Sea. This would play a small but substantive role in de-escalating Russia-Ukraine tensions.

The 1936 Convention Regarding the Regime of the Straits (commonly referred to as the Montreux Convention, after the city in Switzerland where it was negotiated) is a 1936 international agreement that governs the transit of the Turkish Straits for merchant vessels, vessels of war, and aircraft. Negotiated in the shadow of an expansionist Nazi Germany, the Convention includes 29 Articles and three technical annexes that address which warships may enter the Black Sea. It has played an important role in demilitarizing the Black Sea for the past 85+ years. It does so by limiting the size of vessels that may enter the Black Sea, imposing notification requirements on warships transiting the Turkish Straits, and restricting how long non-Black Sea powers can deploy their warships in the Black Sea. Since its inception, Montreux has played an important role in enforcing a rules-based international order in the Black Sea and Turkish Straits.

The U.N. Convention on the Law of the Sea (UNCLOS), the “Constitution of the Oceans”, governs transit passage through international straits around the world. Article 35 clarifies that UNCLOS does not apply to “long-standing international conventions in force.” The upshot: Montreux Convention’s restrictive provisions, and not UNCLOS, govern the Turkish Straits, which enjoy a truly unique legal status in international transit governance.

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If the conflict escalates, the rights of parties other than Ukraine and Russia will also depend on whether other states are adjudged to be co-belligerents. This could cut in one of two ways: if Turkey is not a belligerent but other states join the fight, their access would be compulsorily restricted under Article 19. But if Turkey itself were to join as a belligerent, or if the conflict escalated to the extent that Turkey did feel credibly threatened, Articles 20 and 21 would give Turkey discretion over the passage of warships – including the right to deny return passage to “vessels of war belonging to the State whose attitude has given rise to” Turkey’s belief in imminent danger of war. .................(more)

https://slate.com/news-and-politics/2022/03/nato-ally-turkey-russian-black-sea.html