Turkish and Greek delegations completed another round of confidence-building measures talks in Ankara on October 23, 2025. Officials called the meeting “positive and constructive.” Yet, despite decades of dialogue, strategic trust between the two NATO allies remains low. The root cause lies in Turkey’s increasingly assertive maritime posture embodied in its Blue Homeland (Mavi Vatan) doctrine.
Since 2006, Ankara has treated the waters surrounding Turkey as national territory, elevating maritime disputes into existential claims. Blue Homeland envisions Turkey not as a country with a narrow coastline, but as a maritime power with a vast “homeland” stretching across the Black Sea, the Sea of Marmara, the Aegean, and the Eastern Mediterranean. It seeks control over expansive zones—including continental shelves and exclusive economic zones (EEZs)—based on Ankara’s interpretation of geography and law, challenging international norms and threatening cohesion within NATO.
Since 2006, Ankara has treated the waters surrounding Turkey as national territory, elevating maritime disputes into existential claims.
Rejecting the framework of the United Nations Convention on the Law of the Sea, which Turkey refuses to ratify, Turkish journalist Cengiz Çandar described the “Blue Homeland” as a recipe for “perpetual conflict” in the Eastern Mediterranean. By redefining maritime zones as non-negotiable territory, Turkey risks transforming the Aegean and Eastern Mediterranean from arenas of diplomacy into permanent conflict zones. Instead of pursuing negotiated, lawful settlements with Greece and Cyprus, Ankara chooses revisionism and an irredentist and expansionist vision of maritime sovereignty.
The doctrine now guides Turkish operations and shapes Ankara’s regional policies. In the Eastern Mediterranean, Turkey has invoked Blue Homeland to justify declaring unilateral maritime zones, challenging EEZ agreements between Cyprus, Egypt, and Israel, and signing deals that infringe on the sovereignty of its neighbors.
On November 27, 2019, Turkey and Libya signed a Memorandum of Understanding for maritime boundary and military cooperation, a deal that created an EEZ corridor linking Turkey’s southern coast to Libya’s northeast, cutting through zones claimed by Greece and Cyprus and disregarding islands such as Crete. Greece and Cyprus denounced the agreement as “illegal,” the United States called it “unhelpful and provocative,” and the European Council said it “infringes upon the sovereign rights of third states” and violates the Law of the Sea. Athens further condemned a renewed 2022 Turkey-Libya memorandum on hydrocarbon cooperation as a deliberate escalation undermining regional stability and violating Greece’s sovereign rights.
In the Aegean, Turkey disputes the Law of the Sea principle that islands generate full maritime jurisdiction when near the Turkish mainland. To assert dominance, Ankara repeatedly issues NAVTEX alerts for research vessels operating in contested waters—six between 2024 and 2025 alone—prompting immediate Greek countermeasures. Athens argues that these operations violate its continental shelf, while Ankara insists they are within its self-declared maritime zones.
Despite these provocations, Greek Prime Minister Kyriakos Mitsotakis announced a proposal on October 17, 2025, to revive an Eastern Mediterranean Forum to include Egypt, Cyprus, Libya, and Turkey to reach maritime agreements “based on respect for international law, and especially the Law of the Sea.” Turkey has yet to accept, but its sweeping claims under Blue Homeland and rejection of legal norms make its participation unlikely.
By contesting swaths of the Eastern Mediterranean, Ankara challenges NATO cohesion and regional stability, eroding the trust essential to collective defense.
The implications of Blue Homeland extend beyond bilateral disputes. By contesting swaths of the Eastern Mediterranean, Ankara challenges NATO cohesion and regional stability, eroding the trust essential to collective defense. Its expansionist claims against allies weaken deterrence and inject uncertainty into energy investment and development such as the EastMed corridor. As the region grows crucial for gas exploration and pipelines reducing Europe’s reliance on Russia, Ankara’s aggressive maritime posture threatens both regional order and Western energy security.
More troubling is the ideological entrenchment of Blue Homeland within Turkey itself. The doctrine is now part of curricula, with students learning that Turkey “struggles against unjust claims” denying its rightful maritime interests. Such indoctrination frames maritime disputes as national liberation struggles, cultivating a generation predisposed to view diplomacy as weakness and territorial revisionism as patriotic duty. This transformation suggests Blue Homeland is not merely a bargaining tactic but a long-term ideological project. It blends nationalism, militarism, and geopolitical revisionism—a dangerous mix for a NATO member situated at a strategic crossroads.
For Europe and the United States, the question is not whether Turkey’s ambitions can moderate, but whether they can be contained. If Turkey continues to operationalize Blue Homeland, challenges to Greece and Cyprus will persist, NATO’s internal unity will fray, and the Eastern Mediterranean will remain a flashpoint for confrontation. NATO’s credibility depends on its willingness to confront threats from within as decisively as those from without. Allowing one member to pursue expansionist doctrines that destabilize allies and undermine international law risks setting a precedent no alliance can afford.
