Heightened tensions between Greece and Turkey over Aegean maritime claims

Tensions between Greece and Turkey escalated in early September 2026 following Turkey’s issuance of a maritime directive (NAVTEX 0862/26). Ankara deployed the R/V Tubitak Marmara research vessel to conduct scientific activities south and southwest of Kastellorizo until September 15. In response, the Hellenic Navy’s Heraklion station issued an anti-NAVTEX, declaring the Turkish move illegal because the defined area overlaps with the Greek continental shelf and falls within a Greek-controlled maritime zone.

Separately, Turkey submitted a formal diplomatic note to Greece protesting three spatial planning initiatives announced by Athens in August. These initiatives, concerning tourism (August 7), renewable energy (August 19), and industry/supply chains (August 28), are viewed by Ankara as attempts to create "faits accomplis" in "disputed" Aegean areas. Turkish President Recep Tayyip Erdogan has reinforced this stance, criticizing Greece for allegedly militarizing islands and asserting that Turkey will take necessary actions to protect its interests. The Greek government is currently reviewing the diplomatic note while maintaining its position on sovereign rights. No immediate resolution has been reported, and both nations continue to trade warnings regarding their competing claims over the Aegean maritime status quo.