Asymmetrical or not, Turkey could feasibly perceive Russia's military buildup along the Turkish-Syrian border as a serious threat and invoke its most valuable trump card: the Turkish Straits.

The straits, which consist of the Dardanelles, the Sea of Marmara, and the Bosporus, are a series of waterways in Turkey connecting the Aegean Sea — and the Mediterranean — to the Black Sea.

Turkey, which has full control over the Dardanelles and the Bosporus under the 1936 Montreux Convention, acts as the straits' custodian and regulates the passage of naval ships belonging to Black Sea states.

Russia currently depends on the unrestricted access to the straits afforded it under the Montreux Convention. Through the straits, it sends supplies to Syria from its Novorossiysk naval base in the Black Sea to Russian ports in Tartus and Latakia.