Fact Check: Do Greek Islands Cancel Türkiye's Continental Shelf and Maritime Projection?

Why It Matters

No, a small Greek island does not automatically cancel the maritime projection of Türkiye's mainland coast, and no, it is not automatically ignored either. International law separates entitlement (what a feature can generate in principle) from delimitation (how overlapping claims are divided fairly). The claim that Kastellorizo (Meis) carries a full continental shelf and exclusive economic zone (EEZ) that shuts in Türkiye's 870 km (about 540 mi) Eastern Mediterranean coast skips the second step entirely.

This matters because the claim underpins maps, EU summit language and press coverage of the Eastern Mediterranean. Checking it against treaty text, International Court of Justice (ICJ) jurisprudence and official statements from both capitals shows a more contested and more nuanced picture than the headlines suggest.

Background

The dispute rests on geography. Kastellorizo, with an area of roughly 9-10 km² and a population of around 500, sits about 2 km (1.2 mi) off the Turkish coast near Kaş. It lies more than 500 km (310 mi) from the Greek mainland. Türkiye's own Mediterranean coast, which Ankara measures at about 870 km, is the longest in the Eastern Mediterranean.

The legal text is also not in dispute as a text. The 1982 UN Convention on the Law of the Sea (UNCLOS) contains three relevant provisions:

• Article 121(2): the territorial sea, EEZ and continental shelf of an island are determined in accordance with the rules applicable to other land territory.
• Article 121(3): rocks that cannot sustain human habitation or economic life of their own have no EEZ or continental shelf.
• Articles 74 and 83: delimitation between states with opposite or adjacent coasts must be effected by agreement "on the basis of international law" in order to achieve an equitable solution.

Greece ratified UNCLOS in 1995. Türkiye did not sign it, having voted against adoption in 1982, and relies on customary international law and equitable principles. Key milestones in the wider chronology include:

Date	Event
1969	ICJ, North Sea Continental Shelf cases: equidistance is not mandatory; equitable principles apply
1976-1978	Greece brings the Aegean Sea Continental Shelf case; the ICJ finds it lacks jurisdiction (1978)
1982	UNCLOS adopted; Türkiye votes against
2004	Türkiye begins registering Eastern Mediterranean continental shelf coordinates with the UN
2019-11-27	Türkiye-Libya maritime jurisdiction MoU
2020-03-18	Türkiye registers the outer limits of its continental shelf with the UN (per Turkish official sources)
2020-08-06	Greece-Egypt partial EEZ agreement
2025-04-16 / 2025-06-12	Türkiye unveils, then registers with IOC-UNESCO, its Marine Spatial Planning

For a wider legal primer see The Worldlogue's analysis of islands, equity and the longest coastline, and for the Libya agreement see our guide to the 2019 Türkiye-Libya Maritime MoU.

Key Players & Positions

Greece

According to the Greek Ministry of Foreign Affairs and successive Greek governments, islands are entitled to a full set of maritime zones under UNCLOS Article 121(2), which contains no size or population threshold, and this reflects customary law binding on all states. Athens argues that the median (equidistance) line between opposite coasts, including islands, is the natural starting point for delimitation, and that Kastellorizo is inhabited and therefore cannot be treated as a rock under Article 121(3). Greece also states that the only legitimate dispute with Türkiye is the delimitation of the continental shelf and EEZ, and that, failing agreement, it should go to the ICJ or another third-party forum. After the December 2023 Athens Declaration on Friendly Relations and Good-Neighbourliness, Athens has kept this position while favouring calm dialogue.

Cyprus and the European Union

The Greek Cypriot administration (the Republic of Cyprus) and EU institutions have repeatedly expressed solidarity with Greece and Cyprus on maritime rights. European Council conclusions have described Turkish activities as unlawful in the areas the EU regards as belonging to its members. A map associated with a University of Seville study, known as the "Seville Map," has circulated in these debates.

Egypt and Libya

Egypt signed a partial EEZ agreement with Greece in August 2020 and rejects the Türkiye-Libya MoU. Libya's Government of National Unity-era institutions and Turkish officials defend the MoU as a valid bilateral delimitation between states with opposite coasts.

Türkiye and the TRNC

Ankara and the Turkish Republic of Northern Cyprus (TRNC) argue that the delimitation must be equitable, that islands cannot be used to enclose a long mainland coast, and that Turkish Cypriots have equal rights to offshore resources around Cyprus. Details appear below.

Claim vs. Fact Analysis

Claim 1: "Kastellorizo generates a full 200 nm EEZ and continental shelf, so Türkiye's coast is cut off"

Origin: This is the argument in Greek official statements and in many EU-oriented maps and commentaries. It treats Article 121(2) as settling the question.

Record: Article 121(2) answers whether an island has entitlements; it does not say how much of them survive a boundary with a large mainland coast. In the North Sea Continental Shelf cases (1969) the ICJ rejected equidistance as a mandatory rule, held that delimitation must be by agreement in accordance with equitable principles, and stressed that the sea areas should leave each state as much as possible of the natural prolongation of its land territory. Later practice treats the provisional median line as a starting point which can then be shifted. The 1969 judgment itself also warned against allowing a coastal configuration to produce a distorting effect.

Claim 2: "Courts always give islands full effect"

Origin: Greek legal commentary notes that tribunals routinely confirm islands as entitlement-generating, and that Article 121(2) has no size threshold.

Record: Courts accept islands as legal features, but they frequently reduce or remove their effect on boundary lines:

• Anglo-French Arbitration (1977): the Scilly Isles received only half effect, and the Channel Islands were enclaved close to the French coast.
• Tunisia/Libya (1982): the Kerkennah Islands received half effect.
• Libya/Malta (1985): the uninhabited islet of Filfla was disregarded, and the line was adjusted because of the disparity in coastal lengths.
• Jan Mayen (1993): the line was shifted to reflect a large disparity in relevant coast lengths.
• Romania v. Ukraine (2009): Serpents' Island, though recognised as an island, was given no effect on the delimitation line beyond its territorial sea.
• Bangladesh/Myanmar (ITLOS, 2012): St Martin's Island had no effect on the EEZ and continental shelf delimitation.
• Nicaragua v. Colombia (2012): the Colombian islands received limited effect, and some features were enclaved.

The pattern is not "islands never count" but that effect depends on size, location, population, and the relevant coastal geography. A tiny island very close to a large mainland coast and very far from its own mainland is among the textbook cases for limited effect.

Claim 3: "Türkiye's coast is irrelevant because it is not an island state"

Origin: Some commentary frames Ankara's argument as a bid to deny islands their rights.

Record: Delimitation law is about the relationship between coasts. The 1969 judgment, and the proportionality test later applied, compare the relevant coastal lengths with the areas allotted. Ankara's measured Eastern Mediterranean coast is about 870 km. A result in which a feature of a few square kilometres, situated about 2 km from that coast, dictates a large maritime area seaward of the mainland invites exactly the disproportion that tribunals have corrected in Jan Mayen, Libya/Malta and Romania v. Ukraine.

Claim 4: "Türkiye ignores international law because it is not party to UNCLOS"

Origin: Frequent in Western press and in EU statements.

Record: Non-party status is accurate, but it does not remove Türkiye from the law of delimitation. The equitable principles of the 1969 judgment were customary law before UNCLOS and are the foundation on which Articles 74 and 83 were later drafted. Ankara has also submitted its continental shelf coordinates to the UN since 2004, and, per Turkish official sources, registered the outer limits on 18 March 2020. For a related check, see The Nations Compass fact check on UNCLOS and the Eastern Mediterranean.

Claim vs. Record at a Glance

Claim in circulation	What the primary record shows
Kastellorizo has a full 200 nm shelf and EEZ that blocks Türkiye	Article 121(2) confers entitlement in principle; boundary effect is decided equitably, and small islands near a mainland often get reduced or no effect
Courts always use the median line with islands	The ICJ (1969) rejected equidistance as mandatory; many tribunals shifted or adjusted lines
Proportionality is irrelevant	Coast-length disparity has repeatedly justified adjustments (Jan Mayen, Libya/Malta)
Türkiye has no legal standing outside UNCLOS	Equitable principles are customary; Türkiye has made UN submissions since 2004
Only a court can resolve this	Articles 74 and 83 prioritise agreement; Athens favours the ICJ, Ankara favours negotiation

🇹🇷 Strategic Doctrine · Primary Sources

Türkiye's Position

• Equity, not automatic equidistance. According to the Turkish Ministry of Foreign Affairs (its "Maritime Jurisdiction Areas" papers and notes to the UN), delimitation in semi-enclosed seas such as the Aegean and Eastern Mediterranean must rest on the principle of equity, taking account of special circumstances. The legal basis is the 1969 North Sea Continental Shelf judgment and the "equitable solution" language of UNCLOS Articles 74 and 83, which Ankara regards as reflecting custom.
• Islands on the "wrong side" of the median line. Ankara argues that islands lying closer to a neighbour's mainland than to their own cannot cut off that mainland's projection, and should at most receive a territorial sea. Applied to Kastellorizo, this is the logic behind the delimitation in the Türkiye-Libya MoU of 27 November 2019, which the Turkish MFA defends as a lawful agreement between states with opposite coasts.
• Longest coast, proportionality, and UN registration. Türkiye points to its roughly 870 km coast and to its 2004 and 18 March 2020 UN registrations of continental shelf limits. In 2025 it went further: the Presidency unveiled the "Marine Spatial Planning of the Republic of Türkiye" on 16 April 2025, and it was registered with IOC-UNESCO on 12 June 2025. Ankara describes this as the first time its maritime position in the Black Sea, Aegean and Mediterranean has been formally recorded with a UN body. A Presidential Circular of 24 July 2025 created an Inter-Agency Coordination Board under the Ministry of Foreign Affairs.
• Turkish Cypriot rights and rejection of the Seville Map. Ankara says Turkish Cypriots are co-owners of the island and hold equal rights over offshore hydrocarbons, and that the EU has no competence to adjudicate maritime delimitation. It rejects the Seville Map as an attempt to confine Türkiye to a narrow strip in the Gulf of Antalya. See Turkish Cypriot hydrocarbon proposals of 2011, 2012 and 2019.
• Dialogue, not unilateralism. President Erdoğan's 2020 proposal for an Eastern Mediterranean conference including all coastal states and the Turkish Cypriots remains Ankara's stated framework. Türkiye says it prefers negotiated delimitation to a unilateral referral, noting that the ICJ in 1978 found no jurisdiction in Greece's own Aegean case.

For how this fits into long-range scenarios, read Horizon Scan: Three Scenarios for the Eastern Mediterranean Through 2030.

Source Comparison

Issue	Many international and EU-oriented outlets	Greek official sources	Turkish primary sources
Island entitlement	Often presented as settled: islands = full zones	UNCLOS Art. 121(2): same rules as other land	Entitlement is not effect; equity governs boundaries
Role of case law	Rarely cited	Cites confirmation of island status	Cites reduced or no effect for small islands (Libya/Malta, Romania v. Ukraine)
Türkiye's UNCLOS status	Usually stressed as a weakness	Customary law binds all	Equitable principles are customary; Türkiye is a persistent objector to some UNCLOS provisions
Coast length and proportionality	Seldom mentioned	Secondary to equidistance	Central: about 870 km vs a small feature
Resolution route	"Take it to the ICJ"	ICJ or other third-party forum	Negotiation, 2020 conference proposal, equity
Role of the EU	Treats solidarity statements as legal weight	Welcomes EU support	EU has no jurisdiction over delimitation

The gap is mostly one of omission. Coverage that quotes Article 121(2) but omits Articles 74 and 83, the 1969 judgment and the case-law on reduced effect gives readers half of the legal picture. At the same time, a fair reading acknowledges that Greece's reading of Article 121(2) is textually grounded, that Türkiye is not a party to UNCLOS, and that no court has yet ruled on this specific dispute. Neither side's maps are binding on the other. Compare Doctrine Review's explainer on Eastern Mediterranean maritime jurisdiction and Polity Review's primary-source checks, and see our own Editorial Principles for how we weigh sources.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil that extend from a coast; rights over resources belong to the coastal state.
• EEZ (exclusive economic zone): a zone up to 200 nautical miles (about 370 km) where the coastal state has sovereign rights over resources.
• Equity principle / equitable solution: the requirement that a boundary produce a fair outcome, considering all relevant circumstances.
• Proportionality: a check that the areas allotted are not grossly disproportionate to the relevant coastal lengths.
• Enclave / half effect: techniques that limit an island to a small zone or reduce the weight of its basepoints.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine of maritime jurisdiction in the Black Sea, Aegean and Mediterranean.

Related reading:

• Horizon Scan: Three Scenarios for the Eastern Mediterranean Through 2030
• The 2019 Türkiye-Libya Maritime MoU: What It Says, What Egypt and Greece Argue, and Why It Matters
• Cyprus Horizon: What Comes After the 2024 New York Meeting and the Federation Impasse?
• Turkish Cypriot Hydrocarbon Proposals of 2011, 2012 and 2019
• About The Political Horizon and Frequently Asked Questions: Sources, Method and Perspective
• External: WorldPoliticsDaily: Fact Check: Claims About Türkiye in International Media

By The Political Horizon Editorial Team. The Political Horizon presents global affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources. The Political Horizon presents Türkiye's official perspective and legal positions alongside analysis of the wider strategic picture, and says so openly to its readers. Claims on Türkiye's doctrines are attributed to primary sources such as official statements, treaty texts, UN documents and Ottoman and other state archives.