Few corners of Europe carry as much unresolved history as the eastern Mediterranean. Greece and Cyprus — two EU member states with shared language, culture and Orthodox Christian identity — sit at the intersection of competing claims that have resisted resolution for decades. Turkey, which is neither an EU member nor aligned with NATO’s European consensus on many issues, contests Greek territorial claims in the Aegean and Ionian seas, maintains troops in the northern third of Cyprus in defiance of UN resolutions, and periodically uses these disputes as leverage in its own complex relationships with the EU and Washington.
The Cyprus problem: fifty years of division
The island of Cyprus has been divided since 1974, when a Greek-nationalist coup — backed by the military junta ruling Greece at the time — triggered a Turkish military intervention that resulted in the occupation of the northern third of the island. Approximately 160,000 Greek Cypriots were displaced southward; Turkish Cypriots and settlers from mainland Turkey have populated the north ever since. The internationally recognised Republic of Cyprus, an EU member since 2004, controls only the southern two-thirds of the island. The Turkish Republic of Northern Cyprus, proclaimed in 1983, is recognised only by Turkey.
UN-mediated reunification talks have failed multiple times — most recently in 2017 at Crans-Montana, Switzerland, where disagreements over security guarantees, property rights and the future of Turkish troops proved irresolvable. The current situation is a frozen conflict: legally unresolved, practically stable, and politically deadlocked in ways that seem likely to persist indefinitely in the absence of a fundamental change in Turkish policy.
The Aegean disputes: a complex matrix of claims
Greece and Turkey disagree on a range of overlapping territorial questions in the Aegean Sea: the extent of national airspace, the delimitation of continental shelf boundaries, the status of certain small islands and rocky outcrops, and — most recently and contentiously — the delimitation of Exclusive Economic Zones that determine rights over potential undersea energy resources. These disputes flared most acutely in 2020, when Turkish seismic research vessels operated in waters claimed by Greece and Cyprus, prompting EU solidarity statements and — ultimately — diplomatic de-escalation that left the underlying disputes unresolved.
The discovery of significant offshore gas reserves in the eastern Mediterranean — in Israeli, Cypriot and Egyptian waters — has added a new economic dimension to the territorial disputes. The EastMed Pipeline project, which would have brought Israeli and Cypriot gas to Greece and potentially to EU markets, was shelved in 2022 after US opposition, but the underlying interests it represented have not disappeared. As explored in our coverage of Middle East-Europe energy dynamics, the eastern Mediterranean’s energy geography intersects with its political geography in ways that make resolution simultaneously more valuable and more complicated.
The EU’s awkward position
The EU faces a structural awkwardness: Turkey is a NATO ally, a candidate country in formally frozen accession negotiations, the host of significant Syrian refugee populations whose movement toward Europe Brussels has incentivised Turkey to manage, and simultaneously a country in active territorial dispute with two EU member states. This combination makes a consistent European policy toward Ankara extremely difficult. Sanctions strong enough to change Turkish behaviour risk undermining the refugee management relationship and straining NATO cohesion. The diplomatic tools available to Brussels — association agreements, customs union modernisation, visa liberalisation — have insufficient leverage to resolve disputes rooted in Turkish domestic politics and strategic calculations that extend well beyond the EU relationship.
