>maybe Turkey (which is technically a NATO member but not in particularly friendly terms with the West) decides that it is allowed to control access to the Black Sea
Interestingly, Turkey is allowed -- by the Montreux Convention -- to close the straits between the Black Sea and the Mediterranean to warships and in fact have been doing so since 2022:
>Turkey has closed off the Bosphorus and Dardanelles straits to warships from any country, whether or not they border the Black Sea, following Russia’s invasion of Ukraine. The strait closures will still allow warships through if they are returning to a home base in the Black Sea, according to reporting from Naval News. This would include Russian ships in the country’s Black Sea Fleet. However, the decision to restrict warships, a power given to Turkey by the Montreux Convention of 1936, will likely limit Russia’s ability to move ships from its other fleets to the Black Sea.
Interestingly, Turkey is allowed -- by the Montreux Convention -- to close the straits between the Black Sea and the Mediterranean to warships and in fact have been doing so since 2022:
>Turkey has closed off the Bosphorus and Dardanelles straits to warships from any country, whether or not they border the Black Sea, following Russia’s invasion of Ukraine. The strait closures will still allow warships through if they are returning to a home base in the Black Sea, according to reporting from Naval News. This would include Russian ships in the country’s Black Sea Fleet. However, the decision to restrict warships, a power given to Turkey by the Montreux Convention of 1936, will likely limit Russia’s ability to move ships from its other fleets to the Black Sea.
https://news.usni.org/2022/02/28/turkey-closes-bosphorus-dar...