Explained: How Turkey closing its waters to Russia’s navy could impact the war in Ukraine

The two countries duked it out in Syria. Turkey used drones to kill 100 Russian tanks. Deny them access to the Black Sea.

In WWII the British an American navies owned the Mediterranean Sea, thus Germany could not resupply her army in North Africa by ships. They tried to fly in supplies but that was like a drip of the supplies they needed.

PO1 William "Chip" Nagel
..."Why is this route important to Russia?

Andrew M. Hascher in his paper ‘The Black Sea and the Turkish Straits: Resurgent Strategic Importance in the 21st Century’ writes that “Modern maritime shipping in the Black Sea and Turkish Straits is responsible for a wide variety of goods being brought to the global market. Perhaps most notable are the energy products of Russia, the South Caucasus region, and Turkey. Oil and natural gas are brought from as far away as the Caspian Sea via pipelines, then transit the Black Sea in both ships and further pipelines.”...