Greece and Türkiye in the Aegean
The Aegean argument is now fought with marine parks and energy plans, because the one move that would widen Greek waters, from six nautical miles to twelve, is the move Türkiye's parliament called a cause for war in 1995. Since September 2026 it has also been fought with exercise zones and airspace notices, each side declaring the other's void.
Greek territorial waters in the Aegean stop at six nautical miles. Article 3 of the UN Convention on the Law of the Sea allows twelve, and Greece took twelve in the Ionian Sea after agreements with Italy, never in the Aegean. The reason is a declaration the Turkish parliament adopted unanimously in 1995. It says an extension beyond six miles in the Aegean that would disrupt the balance established at Lausanne would be a cause for war, and grants the government all powers deemed necessary, including military ones.
Greece ratified that convention on 21 July 1995. Türkiye is not among its 172 parties, so the twelve-mile right Greece could use sits in a treaty Türkiye never joined. In January 2026 the Greek foreign minister, George Gerapetritis, told parliament that a further extension of territorial waters would come next, after the maritime agreements Greece concluded with Italy and Egypt. He did not say which waters, and the Aegean is the sea the 1995 declaration names.
Greece and Türkiye have never delimited the continental shelf or the exclusive economic zone between them. The Aegean is narrow, many Greek islands lie close to the Turkish coast, and neither government will accept a line drawn by the other. In the same speech, Gerapetritis said delimitation is the only issue Greece will put on the table, that Türkiye puts others on it, and that Greece will not discuss sovereignty. Each side publishes a document about the sea, and each tells the other that it has no legal effect.
Turkish presidential decisions dated 15 August 2026 created two national marine parks, in the northeast Aegean and the eastern Mediterranean, and were published in the official gazette on 16 August. Athens called them illegal, on the ground that no state may declare protected marine areas beyond its own jurisdiction. On 19 August Greece declared a Special Spatial Framework for Renewable Energy Sources covering the Aegean. Ankara replied the same day that it carried no legal consequences for Türkiye.
On 28 August two Greek F-16s were scrambled against a Turkish drone. Euronews reported that it entered the Athens flight information region and Greek national airspace over the sea between Samothrace and Lemnos. The drone came close to the runway at Alexandroupoli airport as a passenger aircraft prepared to take off. In remarks reported on 4 September, Erdoğan said Greece must stop arming Aegean islands that have demilitarised status.
The marine parks are now signed instruments, not plans. Erdoğan signed two decrees on 15 August 2026 and they were gazetted the next day. The Fethiye-Kaş Marine National Park covers 21,706.03 square kilometres in the eastern Mediterranean off Muğla and Antalya, reaching waters around Kastellorizo, which Türkiye calls Meis. The North Aegean Marine National Park covers 1,742.14 square kilometres off Çanakkale and Tekirdağ, extending toward waters between Samothrace and Lemnos. The Greek embassy in Ankara protested on Thursday 3 September, arguing the boundaries have no legal effect where they run beyond Turkish jurisdiction into what Athens counts as its continental shelf, and Türkiye handed back notes restating its own position. The legal ground is not shared: Greece argues from the Law of the Sea Convention, that no state may unilaterally declare protected areas on the high seas or on another state's shelf, and that islands carry territorial waters, a shelf and an exclusive economic zone. Türkiye has not joined that convention, and argues boundaries should be agreed on equity and geography because the Greek reading would confine the Turkish mainland to a narrow strip of sea. Ankara had made the mirror-image objection to Greek marine parks in July 2025, saying environmental programmes should not be used to advance sovereignty claims.
From September 2026 the argument moved from paper to operations, and the instrument is the airspace notice. Türkiye issued NOTAM A3788/26 designating five large exercise areas in the central Aegean from 25 September to 27 October 2026, running along the 25th meridian. On the Greek account parts of those zones touch or enter Greek national airspace, which Greece measures at 10 nautical miles from its coast, although its territorial waters stop at six. Greece issued a counter-notice disputing Türkiye's authority to direct traffic inside the Athens flight information region, where ICAO rules make Greece responsible, and then NOTAM A3595/26, two areas for air and naval exercises from 12 to 20 October 2026 overlapping the northern part of the Turkish zones. Türkiye answered with NOTAM A4388/26, asking Greece to move boundaries it said overlapped Turkish exercise zones in international airspace, and when Greece refused declared the Greek notice null and void while keeping its own in force. These Turkish positions are reported here from a Greek outlet relaying them secondhand, which is worth knowing when reading them.
”The sovereignty regime in the Aegean is absolutely clear.”
The numbers
What the comparison shows
Where they agree
Turkish security sources say the head of MİT, İbrahim Kalın, met the head of EYP, Themistoklis Demiris, in Athens in late August, and that the two agreed to deepen cooperation against terrorism and organised crime. Ankara names the Athens Declaration on Friendly Relations and Good Neighbourliness of 7 December 2023 as the framework for settling the issues. Athens says in its own statement that it stands for dialogue and good-neighbourly relations.
Where they split
Athens says Greek sovereignty in the Aegean is established by international treaties and that the only open question is delimiting the continental shelf and the exclusive economic zone. Türkiye's foreign ministry lists a set of interrelated Aegean issues instead, among them geographical features whose sovereignty, it says, was never transferred to Greece by treaty.
What nobody is saying
Greece has never said whether the further extension it announced applies to the Aegean. Gerapetritis named no waters in January 2026, and Greece has not extended there in the thirty-one years since the 1995 declaration, so its terms have never been tested.
Who says what
Ties the Greek framework to what he calls the interrelated Aegean issues between the two countries, among them geographical features whose sovereignty, he says, was never transferred to Greece by international treaties. Adds that unilateral acts should be avoided in a semi-enclosed sea, and that Türkiye, as one of its two coastal states, is ready to cooperate.
”this and similar initiatives will not affect Türkiye's legal position on Aegean issues”this and similar initiatives will not affect Türkiye's legal position on Aegean issues
Calls the Turkish spokesperson's claims unfounded and unacceptable, and says Greek sovereignty is established by international treaties and cannot be challenged. Names the delimitation of the continental shelf and the exclusive economic zone as the sole dispute with Türkiye.
”The sovereignty regime in the Aegean is absolutely clear.”The sovereignty regime in the Aegean is absolutely clear.
Says Greece must reverse course and stop arming islands that have demilitarised status, and that Türkiye has acted constructively without getting the same in return.
”Whoever interprets Türkiye's calm and responsible approach as weakness is making a serious mistake.”Whoever interprets Türkiye's calm and responsible approach as weakness is making a serious mistake.
Told parliament in January 2026 that a further extension of Greek territorial waters would come next, after the maritime agreements concluded with Italy and Egypt. He did not specify which maritime areas.
”Today, our sovereignty in the Aegean Sea extends to six nautical miles.”Today, our sovereignty in the Aegean Sea extends to six nautical miles.
Our coverage
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- US unveils $4 billion defence package for Greece as Rubio calls a Greek-Turkish crisis "unimaginable"Friday, 9 October 2026
- Greece and Türkiye trade dueling airspace notices over the AegeanWednesday, 7 October 2026
- Türkiye's Aegean airspace restriction still in force as Ankara prepares maritime lawSaturday, 3 October 2026
- Turkey's new Aegean airspace notice draws a Greek counter-noticeThursday, 24 September 2026
- Türkiye's Denizkurdu drill puts 14,000 personnel across four seas, one designated zone overlaps Cyprus's claimsTuesday, 22 September 2026
- Türkiye launches Denizkurdu-I naval drill across four seas as Aegean tensions rise with GreeceMonday, 21 September 2026
- Aegean dispute widens beyond the naval exercise to air defence and territorial watersSunday, 20 September 2026
- Türkiye launches major naval exercise in the Aegean as Greece raises alert levelSaturday, 19 September 2026
- Fidan warns Greek island militarization is a threat to TürkiyeThursday, 17 September 2026
- Greek PM heads to island near Turkish coast as Erdoğan warns Athens on Aegean armsFriday, 11 September 2026
- Greece and Türkiye trade fresh accusations as Aegean marine park dispute reignitesThursday, 10 September 2026
- Greece formally protests Türkiye's new Aegean and Mediterranean marine parksMonday, 7 September 2026
- Turkish and Greek spy chiefs hold rare Athens meeting over Aegean tensionsSunday, 6 September 2026
- Türkiye and Greece clash again over marine parks in the AegeanSaturday, 5 September 2026
- Türkiye revives Aegean 'gray zones' dispute over Greek tourism planFriday, 4 September 2026
- Erdoğan warns Greece to stop arming Aegean islandsThursday, 3 September 2026
- Greek F-16s intercept Turkish drone near Alexandroupoli as Aegean dispute sharpensSaturday, 29 August 2026
- Greek PM hardens line on Aegean disputes with TürkiyeTuesday, 25 August 2026
- Greece tells Turkey its own Aegean sovereignty is not up for debateSaturday, 22 August 2026
- Ankara rejects any legal effect from Greece's offshore renewables planThursday, 20 August 2026
- Athens condemns Türkiye's two new marine parks in the AegeanTuesday, 18 August 2026
- Ankara says Greece's new Aegean tourism plan has no legal effectSunday, 9 August 2026