Fact Check & Verification· did Turkey close the Bosphorus to Russian warships Montreux Convention

Fact Check: Did Türkiye 'Close the Straits' to Russia Under the Montreux Convention?

Did Turkey close the Bosphorus to Russian warships? Fact check: Türkiye applied Montreux Article 19 to belligerents; commercial passage stayed open.

By Frontline Diplomacy Editorial Team

Published: October 26, 2026

⏱ 9 min read (1,942 words)

The Brief — Key Takeaways

Verdict: partly misleading. Türkiye applied Article 19 of the 1936 Montreux Convention to warships of belligerent states from February 2022, but the Straits were never 'closed to Russia' as a whole.
Commercial shipping kept moving because Articles 2 and 4 of Montreux guarantee freedom of merchant passage in peacetime and in wartime when Türkiye is not a belligerent.
Article 19 contains a home-port exception: belligerent warships separated from their bases may return to them, which is why the restriction is narrower than 'closure' headlines implied.
Türkiye cannot lawfully shut the Straits to a single chosen country; only Articles 20 and 21 give Ankara broad discretion, and only if Türkiye is at war or feels threatened by imminent danger of war.
Ankara says it applies the Convention equally and impartially to all belligerents, while critics in Kyiv call the restriction insufficient and Moscow stresses the treaty's literal terms.

By the Frontline Diplomacy Editorial Team

Why It Matters

The Brief. After Russia's full-scale invasion of Ukraine in February 2022, headlines and social posts said Türkiye had 'closed the Bosphorus and Dardanelles to Russia'. Verdict: partly misleading. Türkiye announced that it would apply the Montreux regime for warships of belligerent states (Article 19), but commercial passage stayed open and the Straits were never closed to Russia as a whole. A second, related claim, that Ankara can shut the Straits to anyone at will, is not supported by the treaty text.

The distinction matters because the Turkish Straits (the Bosphorus, the Sea of Marmara and the Dardanelles) are the only exit from the Black Sea to the Mediterranean. Loose language about 'closing' them can inflate expectations, feed accusations that Türkiye is either 'blocking' or 'enabling' one side, and obscure what a 90-year-old treaty actually allows. This page checks the claims against the Convention text and Turkish official statements.

Primary-source box

Convention Regarding the Regime of the Straits, signed at Montreux on 20 July 1936 (in force since 9 November 1936); registered in the League of Nations Treaty Series (vol. 173). The Turkish Ministry of Foreign Affairs (MFA) publishes the English text on mfa.gov.tr; readers should consult the full text rather than summaries.
Statements by Foreign Minister Mevlüt Çavuşoğlu in late February 2022 and later MFA and Presidency (Cumhurbaşkanlığı) remarks on Montreux, available through the MFA and the Directorate of Communications.

Claim vs. Fact Analysis

Claim 1: 'Türkiye closed the Straits to Russia'

Where it came from. On 27 and 28 February 2022, Ukrainian officials publicly urged Ankara to close the Straits to Russian warships, and Turkish ministers then said Montreux would be implemented. Wire headlines and social posts compressed this into 'Turkey closes straits'.

What the documents show. Türkiye applied Article 19, which concerns warships only. Çavuşoğlu said at the end of February 2022 that Türkiye would implement Article 19 of the Convention, and Ankara notified the parties on 28 February 2022. The same statements stressed that merchant shipping was not affected. Nothing in Article 19 touches merchant vessels.

Verdict: Misleading. A restriction on belligerent warships is not a closure of the Straits to a country.

Claim 2: 'Türkiye can close the Straits to anyone it chooses'

What the treaty says. Montreux is a multilateral treaty with a reciprocal structure. Its starting principle (Article 1) is freedom of transit and navigation by sea in the Straits. Türkiye holds sovereignty over the Straits and the right to remilitarize them (restored by the Convention), but the right to regulate passage is defined by the text.

Merchant ships, peacetime (Article 2): complete freedom of transit and navigation, day and night, irrespective of flag or cargo, with only limited health and administrative formalities.
Merchant ships, wartime with Türkiye neutral (Article 4): the same freedom continues.
Warships in peacetime (Articles 10–18): light surface vessels, minor war vessels and auxiliary vessels of any flag may pass, subject to prior notification through diplomatic channels (eight days for Black Sea states, fifteen days for others). Non-Black Sea states face limits on the aggregate tonnage in transit (Article 14), a ceiling on tonnage in the Black Sea and a maximum stay of 21 days (Article 18). Submarines of non-Black Sea states and aircraft carriers are not permitted passage; Black Sea states have special provisions for capital ships and for submarines returning to base or going for repair.
Wartime provisions: Articles 19, 20 and 21, explained below.

No clause lets Türkiye single out one named state in peacetime. The Convention also has no mechanism for unilateral amendment; changes require the procedure set out in its final provisions and the agreement of the contracting parties.

Verdict: False. Ankara has discretion only in the circumstances the treaty lists.

Claim 3: 'Türkiye should have closed them fully' (or 'is to blame for not doing so')

The three wartime articles

Article	Situation	What it provides
19	Türkiye is not a belligerent, and a war is under way	Warships of non-belligerent states keep passage rights under the peacetime rules. Warships of belligerent states may not pass, with stated exceptions (including a League of Nations-era mutual-assistance clause now widely regarded as dormant). Belligerent warships separated from their bases may return to the bases of their own countries. No hostile acts in the Straits.
20	Türkiye is a belligerent	The peacetime warship rules lapse; passage of warships is left entirely to Türkiye's discretion.
21	Türkiye considers itself threatened with imminent danger of war	Türkiye may apply Article 20 as if it were a belligerent.

The broad 'close it' power therefore belongs to Articles 20 and 21, which depend on Türkiye being at war or itself threatened. Türkiye has not said either condition applies. Article 19, the provision Ankara chose, is the one designed for a war between other states.

The home-port exception. Article 19 allows belligerent warships to return to their home bases. In practice this means the rule hinders a belligerent from bringing new warships into the Black Sea from outside, while ships already stationed there are not locked out of their own ports. Turkish officials have described this as part of the Convention's design, not a loophole. A further complication is that Türkiye does not recognize Russia's 2014 annexation of Crimea, so questions can arise about what counts as a 'home' base; the public record does not provide a full account of individual passages, so this page does not cite counts.

Is a formal declaration of war required? Article 19 speaks of 'time of war' without defining it. Russia describes its actions as a 'special military operation' and has not formally declared war on Ukraine. Some analysts argue a formal declaration is needed; others hold that war in fact is enough. Ankara's practice, in line with its public statements, treats the situation as a war for the purposes of Article 19.

Verdict: Legally contested, not a simple failure. Closing the Straits entirely would have required stepping outside Article 19 into territory the treaty reserves for Türkiye's own belligerency or imminent danger of war.

Claim 4: 'If merchant ships still pass, the restriction is meaningless'

The Convention protects commercial transit deliberately. Ships carrying Russian, Ukrainian and other cargoes continued to use the Straits, and the Black Sea Grain Initiative, signed in Istanbul in July 2022 by Türkiye, Russia, Ukraine and the United Nations, depended on that freedom of merchant passage. The initiative's Joint Coordination Centre in Istanbul inspected ships, but the passage right itself comes from Montreux, not from Ankara's goodwill. Russia suspended its participation in July 2023.

Timeline

Date	Event
1936-07-20	Montreux Convention signed
1936-11-09	Convention enters into force
2022-02-24	Russia launches its full-scale invasion of Ukraine
2022-02-27	Ukrainian officials publicly urge Türkiye to close the Straits to Russian warships
2022-02-28	Ankara notifies the parties that it will apply Article 19
2022-07-22	Black Sea Grain Initiative signed in Istanbul
2023-07	Russia suspends participation in the Initiative

The restriction has not been publicly lifted, and later reporting, including remarks by Turkish officials, describes it as applying to all belligerent states equally.

What to Watch

Whether any signatory formally proposes changes to the Convention (unlikely; none has been amended since 1936).
Further public clarification from Ankara on how the home-port exception is applied.
Maritime traffic and security in the Black Sea if talks on ceasefire arrangements resume (see Istanbul Talks Between Russia and Ukraine).

🇹🇷 Diplomatic Role · Mediation & Official Record

Türkiye's Position

Implementation in good faith and equally. The Turkish MFA and the Presidency (Cumhurbaşkanlığı) have said that Türkiye applies Montreux in good faith, impartially and to all belligerents alike, riparian or not. Basis: Article 19 and the Convention's reciprocal structure.
Montreux as a pillar of Black Sea stability. Ankara says the 1936 regime has balanced the security interests of littoral and non-littoral states for decades and should not be reopened. Basis: the Convention text and repeated Turkish statements on its preservation.
Commercial passage is protected. Turkish officials have stated that merchant shipping is not subject to Article 19, in line with Articles 2 and 4. Basis: the Convention text.
Channels with both Moscow and Kyiv stay open. The Turkish government says its Montreux implementation is compatible with its mediation efforts, including the Istanbul talks and the Black Sea Grain Initiative (see Türkiye as Mediator). Basis: MFA and Presidency statements.
Honest limits. The Convention did not end or shorten the war. Critics on both sides regard the restriction as either insufficient or excessive, and Ankara's own position is that it is bound by the text of the treaty.

Source Comparison

Source type	Typical framing	Where it is imprecise
Wire services and Western outlets	Generally accurate in body text ('Türkiye will implement Montreux, restricting warship passage'); headlines sometimes 'Turkey closes Straits'	'Closes' implies all traffic, including merchant ships
Russian state media and officials	Emphasize that Montreux must be applied as written, citing the return-to-base provision; criticize Western calls for reinterpretation	Tend to downplay the wartime restriction on new entries
Ukrainian officials	Called for full closure to Russian warships and welcomed Ankara's step as important but, in some statements, insufficient	Closure to a single state is not provided for in Article 19
Turkish primary sources (MFA, Presidency, Directorate of Communications, Anadolu Agency)	Use treaty language: 'implementing Article 19', equal application, protection of commercial passage	Official statements do not publish detailed passage records

The shorthand 'closed' is imprecise in three ways: it ignores merchant traffic, it ignores the home-port exception, and it suggests a power Ankara does not hold in peacetime or under Article 19. The more accurate phrase is 'restricted passage of belligerent warships'.

Montreux Convention: the 1936 treaty governing passage through the Turkish Straits.
Turkish Straits: the Bosphorus, Sea of Marmara and Dardanelles.
Belligerent: a state party to an armed conflict.
Article 19: the clause on warships of belligerent states when Türkiye is not at war.
Home-port exception: the provision letting separated belligerent warships return to their own bases.

Frontline Diplomacy covers international diplomacy with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' (labelled 'Türkiye's Role' elsewhere on the site) reflect official Turkish policy as stated by Turkish government sources.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

World Agenda Review: The Montreux Convention and the Black Sea: How Türkiye Applied the Straits Regime in the Russia–Ukraine War — How Türkiye applied the 1936 Montreux Convention in the Russia–Ukraine war: Article 19, limits on closing the Straits, Istanbul diplomacy and the grain deal.
Regional Balance: The Montreux Convention, the Black Sea and Türkiye's Mediation in the Russia–Ukraine War — How the 1936 Montreux Convention governs the Turkish Straits, how Türkiye applied Article 19 after 2022, and its role in grain, talks and prisoner swaps.
Polity Review: Montreux Convention, the Black Sea and Türkiye's Role in the Russia–Ukraine War — How the 1936 Montreux Convention governs the Turkish Straits, how Türkiye applied Article 19 in 2022, and its Black Sea grain and mediation role.

Frequently asked questions

Did Türkiye close the Bosphorus and Dardanelles to Russia in 2022?

No, not in the sense the headlines implied. Türkiye announced in late February 2022 that it would apply Article 19 of the Montreux Convention, which restricts passage of warships of belligerent states. Merchant shipping, including Russian-linked trade, continued under Articles 2 and 4.

Can Türkiye shut the Straits to any country it wants?

No. The Convention is a reciprocal treaty and Türkiye can exercise broad discretion over warship passage only under Article 20 (if Türkiye is a belligerent) or Article 21 (if it considers itself threatened by imminent danger of war). Merchant passage is protected in peacetime and when Türkiye is neutral.

What is the home-port exception in Article 19?

It lets belligerent warships that have become separated from their bases return to the bases of their own countries. In practice this limits the entry of additional belligerent warships from outside the Black Sea, while ships based there are not barred from returning to port.

Does Article 19 require a formal declaration of war?

The text refers to 'time of war' without defining it, so scholars disagree. Some argue a formal declaration is needed, while others say a state of war in fact is enough. Ankara has applied Article 19 in practice, and Russia, which has not formally declared war, has raised the home-port exception rather than challenging the principle.

Why did the Black Sea Grain Initiative work if the Straits had restrictions?

Because the restrictions concern warships, not cargo vessels. Montreux guarantees merchant passage, and the 2022 Istanbul agreement added an inspection and coordination mechanism for grain ships. Russia suspended its participation in July 2023.

Did the Montreux restrictions stop the war?

No. The Convention governs passage through the Straits; it does not address the war itself. Supporters see it as limiting escalation in the Black Sea, while critics argue it should have been stricter or that it should not have been applied at all.

Cross-Publication Perspectives & Cited Research

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