Turkey's NATO Position Is More Complicated Than Ever

Turkey's strategic positioning within NATO has always been uncomfortable. It controls the Bosphorus and Dardanelles, runs the alliance's second-largest army, and hosts critical infrastructure at Incirlik. It has also purchased Russian air defence systems and maintained trade with Moscow throughout the war in Ukraine.

Turkey's purchase of the Russian S-400 air defence system in 2019 remains the most disruptive decision in the alliance's recent history. The US removed Turkey from the F-35 programme. The S-400 sits in warehouses, never operationally deployed — an expensive purchase Turkey has neither used nor abandoned. Erdoğan's government shows no inclination to resolve the impasse on terms acceptable to Washington.

Turkey's invocation of the Montreux Convention to close the Bosphorus to warships after February 2022 was one of the most consequential military decisions of the early war period. It prevented Russia from reinforcing its Black Sea Fleet — entirely at Turkey's discretion, a reminder of how dependent the alliance is on Ankara's choices.

NATO's leverage over Turkey is more limited than it might appear. Expulsion is legally impossible — the Washington Treaty has no exit mechanism. Sanctions would damage alliance cohesion more than Turkish behaviour. The practical toolkit: sustained diplomatic pressure, economic incentives tied to F-35 restoration, and patience for domestic political change that might produce a more predictably Western-oriented government.

It has also purchased Russian air defence systems, maintained trade with Moscow throughout the war in Ukraine, and used its veto power to delay the accession of Sweden and Finland.

Turkey's purchase of the Russian S-400 air defence system in 2019 remains the most concrete manifestation of the alliance's dysfunction. The United States expelled Turkey from the F-35 programme, imposed CAATSA sanctions, and demanded the S-400 be deactivated or transferred. Turkey has done none of these things. The systems sit in storage, technically inactive, but available. The question of what happens when a NATO ally possesses a Russian air defence system that could potentially be used to track allied aircraft has never been answered.

Turkey's management of the Bosphorus and Dardanelles under the Montreux Convention has been one of the most consequential decisions of the Ukraine war. By invoking Montreux to close the straits to warships of belligerent states after February 2022, Turkey prevented Russia from reinforcing its Black Sea Fleet while also preventing Western naval vessels from entering. This decision was consistent with Turkey's self-defined role as a neutral facilitator — and it infuriated both sides.

The key to understanding Turkish policy is recognising that Erdoğan does not see NATO membership and Russian engagement as contradictory. He sees them as complementary levers. Being in NATO gives Turkey protection and access to Western technology and markets. Engaging Russia gives Turkey energy security, grain deals, and a role as indispensable mediator that it could not claim as a purely Western-aligned state.

NATO has historically managed Turkey through a combination of deference, side payments, and avoidance of direct confrontation. The logic was that Turkey's strategic value — controlling the Straits, hosting Incirlik, running the second-largest army — outweighed the costs of its behaviour. That calculation is becoming harder to sustain as the behaviour escalates and the cost of tolerance rises.