Fact-check: Is the Turkish Navy blocking Russian ships from crossing the Bosphorus Strait?

Multiple social media users have shared alarming posts that seem to show a fleet of Turkish warships blocking the passage of Russian vessels on the Bosphorus Strait. Some of them believe this is a declaration of war on the Kremlin.

“The Turkish Navy begins a blockade of the Bosphorus Strait, if Russian ships are prevented from passing it would be a declaration of war,” tweeted one account on the social media platform X.

The Bosphorus Strait is a significant shipping route and is the only way countries such as Russia and Ukraine can reach the Mediterranean Sea from the Black Sea. 

The video shared along with the viral post claimed one hundred Turkish ships are currently blocking Russia’s access to the Mediterranean, which the users said violates the Montreux Convention. 

The Cube took a closer at these videos and we found these clips, in reality, show the celebration of Turkey’s centenary on 29 October 2023. 

According to multiple reports, the celebration included a fireworks and drone show in Istanbul as well as a procession of one hundred navy ships on the Bosphorus. 

Turkey had already closed the Bosphorus to Russia

The second point is Ankara had already blocked access to Russian warships after the full-scale invasion of Ukraine in February 2022. 

Kyiv asked the Turkish government to close the Bosphorus Strait to Moscow and, after some hesitation, Ankara banned Russian warships from transiting through these waters.

However, the warships were still allowed to return to their home bases in the Black Sea.

But some reports have accused Russia of transporting hidden war equipment in cargo ships, which are still allowed to transit through these waters. 

A report published by NATO in October 2023 claimed Russia is operating a ghost ship to swerve these restrictions. 

Not a violation of the Montreux Convention of 1936

Finally, closing the strait off to Russia does not violate the 1936 Montreux Convention. 

The treaty covers the various straits that connect the Mediterranean Sea with the Black Sea and has been ratified by the League of Nations, the failed predecessor of the United Nations. The treaty has remained unchanged since it has been ratified. 

Here’s how the treaty works: Turkey guarantees freedom of passage for all civilian and commercial vessels during peacetime. 

Military ships can also pass through, under certain conditions, and only if advance warning is given.

According to Article 19, when there’s a war that doesn’t involve Turkey, warships from the warring states can’t use the straits — unless they’re returning to home bases in the Black Sea.

Turkey has the discretion to close the strait to warships of all nations party to a conflict. It may also do so if it fears an “imminent danger of war.”