Greece–Turkey (Aegean)

What it is

The Greece-Turkey Aegean dispute is a cluster of five interlocked sovereignty contests between two NATO member states. Territorial waters: Greece holds its limit at 6 nautical miles, entitled under UNCLOS (1982) to extend to 12nm, but Turkey's parliament voted in June 1995 that any such extension is a casus belli; a 12nm Greek limit would cover roughly 71 percent of the Aegean. Airspace: Greece asserts 10nm above its 6nm territorial waters; Turkey recognizes only 6nm. Continental shelf and EEZ: Greece claims a median line with islands carrying full weight, grounded in UNCLOS (ratified by Athens in 1995, never by Ankara); Turkey argues islands near its coast should carry reduced entitlement under equity principles. Island demilitarization: Turkey argues the Treaties of Lausanne (1923) and Paris (1947) imposed arms limits on eastern Aegean islands that Athens has violated; Greece says Turkish threats justify its forces there. Athens Flight Information Region: Turkey disputes the requirement to file advance notice for military flights through the ICAO zone Athens manages. None of the five disputes has a negotiated resolution.

History

The 1923 Treaty of Lausanne confirmed Greek sovereignty over the eastern Aegean islands; the 1947 Treaty of Paris transferred the Dodecanese from Italy to Greece, placing Greek territory within visual range of the Turkish coast. A 1987 standoff over Aegean oil permits nearly escalated to armed confrontation. The 1996 Imia/Kardak crisis, a standoff over two uninhabited islets, killed three Greek military officers. Formal "exploratory talks" between foreign-ministry officials began in 2002; more than 60 rounds have since taken place without a framework agreement. Turkey's "Blue Homeland" (Mavi Vatan) doctrine, embraced publicly by President Recep Tayyip Erdogan's government by 2020, formalized Ankara's rejection of UNCLOS-based delimitation. The same year Turkey deployed the Oruç Reis seismic-survey vessel into waters Greece claims as its continental shelf, the sharpest crisis in a generation; Greece and Egypt responded by signing their own EEZ delimitation in August 2020.

Current state

A measured détente began after the devastating February 2023 earthquake in southeastern Turkey, when Athens offered rapid humanitarian assistance. Greek Prime Minister Kyriakos Mitsotakis and Erdogan met at the Vilnius NATO summit in July 2023 and signed the "Vilnius Declaration," committing to a positive agenda on trade and tourism. Erdogan visited Athens in December 2023, the first such visit in two decades. Military confidence-building talks resumed in Thessaloniki in April 2025, covering joint disaster exercises and communication-line upgrades, with a follow-on round in Ankara in October 2025. The underlying disputes remain legally unresolved: no exploratory-talks session has produced a draft delimitation text. In May 2026 Turkey's ruling AKP introduced a draft Maritime Jurisdiction Areas Law that would empower Erdogan to declare a 200nm EEZ and explicitly deny islands equal continental-shelf weight, reopening the confrontation. See トルコのEEZ法案がギリシャとのエーゲ海対立を再燃させる.

Relationships

Both countries are NATO members, providing a political floor but not a resolution: the alliance has repeatedly deferred to bilateral dialogue. Greece is an EU member; Turkey's accession process stalled formally in 2016, limiting Brussels's leverage. Cyprus, a third party, runs through the whole dispute: Ankara does not recognize the Republic of Cyprus, contests its EEZ, and has occupied the island's north since 1974. The United States has pressed both sides toward dialogue without offering formal mediation.

What to watch

• Whether Turkey's May 2026 draft EEZ law passes the Grand National Assembly and Erdogan formally declares a 200nm zone, forcing Greek and EU legal counter-moves.
• Progress or collapse in the exploratory-talks track: whether 60-plus rounds ever produce a delimitation text or a referral to the International Court of Justice.
• The rate of aerial and naval incidents in the Aegean, a daily friction point that has caused casualties even during diplomatic thaws.
• Cyprus reunification talks, structurally linked because a settlement would remove one of Turkey's main levers against Greek maritime rights.