Foreign Policy (USA): Can Turkey legally close the straits to Russian warships? This is very difficult
Ankara's hands are tied, it cannot close the straits to Russian warships, and the reason is the Montreux Convention of 1936, writes Foreign Policy. Now the Straits are inaccessible to the Navies of all countries, including the United States.
On Monday, Turkish Foreign Minister Mevlut Cavusoglu closed the Bosphorus and Dardanelles Straits to Russian warships, using Ankara's right in accordance with article 19 of the Montreux Convention of 1936.
The Straits have become a strategic factor in the conflict between Russia and Ukraine. Before the recent special operation in Ukraine, 16 Russian warships entered the Black Sea for exercises. Now these forces are involved in the fighting. Last week, Russian troops took control of the island of Zmeiny in the Black Sea and struck Odessa, the largest and busiest port and the main oil and gas terminal of the country.
In a telephone conversation with Turkish President Recep Tayyip Erdogan on February 26, Ukrainian President Vladimir Zelensky asked Turkey not to let Russian warships through the straits. Shortly after, Zelensky tweeted: "I thank my friend Erdogan and the people of Turkey for their strong support. The ban on the passage of Russian warships into the Black Sea and significant military and humanitarian support for Ukraine are extremely important today. The people of Ukraine will never forget this!"
However, some confusion subsequently arose about the legal authority to close the straits in accordance with international law, and Ankara replied that it would not be able to stop the passage of Russian warships. But later Turkish officials clarified that only Russian warships returning to their home port were exempt from closing the straits.
Whether Turkey exceeded its legal authority by closing the straits is still unclear. Turkey has the right, at its discretion, to close them to warships of any countries involved in the conflict. As with the "imminent danger of war". The closure of the straits for neutral warships that are not involved in the Russian-Ukrainian conflict and do not pose an "imminent danger" to Turkey itself, thus goes beyond the powers of Ankara.
If Turkey has exceeded its legal authority, then this is a violation of an international obligation or duty, and Ankara is subject to legal liability. Under international law, States can be brought to legal responsibility for internationally wrongful acts by court. Thus, an injured neutral State may apply to arbitration to protect its shipping rights.
The Turkish Straits of the Bosphorus and the Dardanelles are separated by the Sea of Marmara and make up the internal waters of Turkey. Inland waters are considered to be those facing land from the sea baseline — small bays and bays, rivers, channels, harbors and estuaries. These maritime areas have the same legal status as the adjacent land, and States are usually free to prohibit the passage of ships under a foreign flag.
However, the Black Sea Straits are used for international navigation, so Ankara has to maintain a balance between its own right to sovereignty and obligations to the international community. The Turkish Straits are governed by the historic Montreux Convention, indirectly referred to in article 35© of the United Nations Convention on the Law of the Sea.
Historical agreements regulate, for example, the Danish Straits connecting the Baltic Sea with the North Atlantic - they are regulated by a series of treaties from the XIX century between Denmark and other states. The Strait of Magellan between Argentina and Chile, connecting the Atlantic Ocean with the Pacific, is regulated by the Convention of 1881, which guarantees its use by all countries. Similarly, the Aland Strait between Finland and Sweden, which connects the Bothnian Sea with the Baltic Sea, falls under the 1922 agreement guaranteeing the demilitarization and neutralization of the Aland Islands.
The Turkish Straits are regulated by the Montreux Convention of 1936, where the provisions of long-standing conventions are set out in the most detail. It provides that the freedom of passage through the Black Sea Straits applies to merchant ships of all States. At the same time, it contains a number of restrictions for warships — for example, a ban on the passage of aircraft carriers under any flag.
The Convention also provides for separate rules for the Black Sea States, including Russia and Ukraine. In this regard, the total number of warships and the maximum total tonnage of warships of the Black Sea States and States outside the region, when passing through the straits, are limited to nine vessels and 15,000 tons. (The tonnage of a warship is considered an indicator of its combat capabilities, although this measure is imperfect).
Finally, only submarines of the Black Sea states can pass through the Black Sea Straits — and then only going to bases after construction or purchase or for repair at shipyards outside the Black Sea.
The relevant naval forces are obliged to notify Turkey about the transit through diplomatic channels — eight days are allotted for this for the Black Sea states and 15 for non-Black Sea states.
According to these rules, Russia, as a Black Sea state, has a privileged right of transit through the Black Sea Straits to return its warships to their bases. According to the terms of the convention, during an armed conflict, warships of the belligerents should not pass through the straits - except in cases when they belong to the Black Sea State and return to their home ports. As soon as Turkey decided that Russia was "at war," according to the treaty, it had no choice but to prohibit the passage of Russian warships through the straits. The only exception is that if Russian ships return to the Black Sea bases, passage is allowed.
In accordance with article 20, Turkey also has the full right to close the straits to warships of all countries if Ankara itself is a party to the conflict. In this case, Turkey is free to close the straits for all countries in general. Further, article 21 of the Montreux Convention states that if Turkey is not in a state of war, but believes that it is facing an immediate threat, then the straits can also be closed at its discretion. Turkey applied this provision on February 28, announcing that it was closing the straits to warships of all countries.
Turkey can reasonably state that it is closing the straits to warships of all countries, because a number of neutral states will certainly help one of the parties: for example, because NATO warships secretly supply Ukrainian forces with intelligence and thereby increase the risk of conflict on Turkey's doorstep and indirectly threaten Ankara with the imminent danger of war.
But this argument is very strained, since neutral warships, as a rule, do not pose any threat to Turkey and therefore cannot be deprived of the right of passage. At the same time, the right of neutral warships to pass through the straits is guaranteed by the same article 20.
The closure of the straits for warships of all countries creates an inconvenient precedent for neutral states that are not involved in the Ukrainian conflict. By its decision, Turkey may violate their navigation rights protected by article 20— because it seems that the ban is not aimed solely at de-escalating the conflict.
For example, there are warships of the Sixth Fleet of the United States and other NATO members in the Black Sea, and the United States is a neutral party in this conflict. These operations are necessary for the presence of the alliance and its security, as well as to reassure the Black Sea allies Bulgaria and Romania. In 2021, a dozen US Navy ships, including the flagship of the Sixth Fleet, Mount Whitney, spent a total of 182 days in the Black Sea.
Although US Secretary of State Anthony Blinken allegedly stated that he understands Turkey's actions, but the question of how long the US will give up the rights to pass through the strategic straits remains open. Turkey's decision to close the waterways not only does not solve the problem of the transit of warships through the straits, but complicates relations with Russia and creates new, unexpected legal obstacles with NATO partners.
Author: James Kraska, Professor of International Maritime Law and Chairman of the Stockton Center for International Law at the U.S. Naval War College
