Fact Check: Can a Few Small Islands Cancel the Continental Shelf of a Country with the Longest Coastline?

Why It Matters

No, islands do not automatically cancel the continental shelf of a state with a long mainland coast. Islands can generate maritime entitlements in principle, but when two states' claims overlap, delimitation practice has repeatedly reduced, or entirely disregarded, the effect of small islands that sit in front of a larger neighbour's coast. The distinction between having an entitlement and getting full effect in a boundary is the core of the dispute between Türkiye, Greece and the Republic of Cyprus (the Greek Cypriot administration).

The claim shapes headlines, EU statements and map graphics about the Aegean and Eastern Mediterranean. Readers need the primary legal texts and case law to judge it. This page does not re-run the Seville Map or UNCLOS-membership fact checks; it focuses on the islands argument. For the wider picture, see Three Seas, One Coastline: Türkiye's Maritime Jurisdiction in the Aegean, Black Sea and Mediterranean.

Claim vs. Fact Analysis

Where the claim circulates

The claim appears in official Greek and Greek Cypriot statements, in think-tank explainers, in map graphics that draw full 200-nautical-mile (about 370 km) zones around small islands, and in social media posts about 'Turkey's illegal claims'. It is typically phrased as: islands, however small or remote, generate a full continental shelf and EEZ, so the mainland coast of Türkiye is irrelevant. Four distinct claims are bundled in that sentence, and they should be tested separately.

Claim 1: 'Islands automatically generate a full continental shelf and EEZ'

Fact: partly true as to entitlement, false as to automatic full effect. Article 121(2) of the 1982 UN Convention on the Law of the Sea (UNCLOS) says islands have a territorial sea, EEZ and continental shelf like other land territory. Article 121(3) then states that rocks which cannot sustain human habitation or economic life of their own have no EEZ or continental shelf. The ICJ stated in Nicaragua v. Colombia (2012) that the Article 121 regime reflects customary international law, which Greece cites. That entitlement, however, is only the starting point.

When entitlements overlap, Articles 74 and 83 require delimitation 'by agreement on the basis of international law... in order to achieve an equitable solution'. Nothing in these articles says an island's full 200-nautical-mile projection prevails over a neighbour's mainland coast.

Claim 2: 'Islands keep full effect when a boundary is drawn'

Fact: international practice points the other way for small islands. The following decisions are widely cited:

• North Sea Continental Shelf (ICJ, 1969): equitable principles and the avoidance of distortion by coastal irregularities, with proportionality as a check.
• Anglo-French Arbitration (1977): the Channel Islands were confined to a 12-nautical-mile enclave (about 22 km) around them, and the Scilly Isles received only half effect.
• Tunisia/Libya (ICJ, 1982): the Kerkennah Islands were given half effect.
• Libya/Malta (ICJ, 1985): the uninhabited islet of Filfla was disregarded in computing the provisional line, and the line was adjusted for the large disparity in coastal lengths.
• Qatar v. Bahrain (ICJ, 2001): the tiny feature Qit'at Jaradah was disregarded in drawing the line.
• Romania v. Ukraine (ICJ, 2009): Serpents' Island, though recognised as an island, had no effect on the continental shelf and EEZ boundary beyond its 12-nautical-mile territorial sea.
• Bangladesh/Myanmar (ITLOS, 2012): St Martin's Island was given no effect on the EEZ and continental shelf boundary.
• Nicaragua v. Colombia (ICJ, 2012): Colombia's small islands were largely enclaved and restricted, given the mainland coastal geography.

The record is not uniform. In Jan Mayen (1993), a substantial island with its own coast received significant effect. Outcomes depend on size, population, location and the coastal relationship, which is why courts talk about 'relevant circumstances'. The point is that no rule awards full effect automatically.

Claim 3: 'The mainland coast is overridden and its length is irrelevant'

Fact: coastal geography and proportionality are central to the legal test. Modern jurisprudence, set out in Romania v. Ukraine (2009), follows three stages: draw a provisional equidistance line, consider whether relevant circumstances call for adjustment, and then test for gross disproportionality between the ratio of coastal lengths and the ratio of maritime areas allocated. Coastal length is therefore not an afterthought but a formal check.

The geography of the Eastern Mediterranean is unusual. Türkiye's coastline on that sea is about 870 km (roughly 540 miles), the longest of any state on it. Kastellorizo (Meis), the island at the centre of the debate, lies about 2 km (1.2 miles) from the Turkish mainland and well over 500 km (310 miles) from the Greek mainland, and has a population in the hundreds. Ankara argues that giving such an island a full shelf would project a distant state's zones across the front of Anatolia. Whether a tribunal would agree is a legal question that only adjudication or agreement can settle, but the factors involved (size, population, proximity, coastal-length disparity) are those that have led courts to reduce island effect elsewhere.

Claim 4: 'The median line is the rule'

Fact: equidistance is a method, not a binding rule. The 1958 Geneva Convention on the Continental Shelf referred to equidistance in the absence of agreement or special circumstances, but UNCLOS Article 83 dropped that formula in favour of the equitable solution standard. Courts begin with a provisional equidistance line because it is objective, then adjust. In the Aegean, the ICJ never reached the merits: in the Aegean Sea Continental Shelf case it found on 19 December 1978 that it lacked jurisdiction. There is therefore no binding judicial ruling on Greek–Turkish delimitation.

What Athens and Nicosia say

The Greek Ministry of Foreign Affairs maintains that Greek islands, like any other land territory, generate a territorial sea, continental shelf and EEZ under UNCLOS and customary law, and that Türkiye's objections have no legal basis. Athens states that the only dispute with Türkiye is the delimitation of the continental shelf and EEZ and has repeatedly proposed taking it to the ICJ. Greece has also concluded delimitation-related agreements, including the partial EEZ agreement with Egypt signed on 2020-08-06.

The Republic of Cyprus likewise states, through its Ministry of Foreign Affairs, that it exercises sovereign rights over its EEZ as an island state and EU member, citing its agreements with Egypt (2003), Lebanon (2007) and Israel (2010). Ankara rejects these on two grounds: they overlap with Türkiye's continental shelf, and they ignore the equal rights of Turkish Cypriots. The Greek and Greek Cypriot positions are legally argued and should be represented as such. The disagreement is about how much weight islands carry in an equitable delimitation, not about whether islands have any entitlement.

Further analysis is in The Worldlogue: Do Islands Generate a Full Continental Shelf? The Equity Principle and Türkiye's Longest Coastline and Doctrine Review: Eastern Mediterranean Maritime Jurisdiction: Continental Shelf, EEZ and the Blue Homeland.

Source Comparison

The main framing gap is that media often present the claim as settled law. The primary record shows a contested question where equity and relevant circumstances matter, and where the mainland coast counts. A fuller comparison of recurring claims is in WorldPoliticsDaily: Fact Check: Claims About Türkiye in International Media. For how geography drives Ankara's wider policy, see Türkiye's Strategic Meridian: How Geography Shapes Grand Strategy from the Mediterranean to the Caucasus.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coast; coastal states exercise sovereign rights over its resources.
• Exclusive economic zone (EEZ): a zone up to 200 nautical miles from baselines in which the coastal state has sovereign rights over natural resources.
• Delimitation: fixing a boundary where entitlements overlap, by agreement or adjudication.
• Equidistance / median line: a line every point of which is equally distant from the nearest points on each coast; a starting point, not a rule.
• Relevant circumstances: factors such as coastal length, geography, islands and conduct that may adjust a provisional line.
• Proportionality: a final check on whether the areas allocated are grossly disproportionate to coastal lengths.
• Enclaving: limiting an island to a territorial-sea belt around it, as in the Channel Islands.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine of maritime jurisdiction in the Black Sea, Aegean and Mediterranean.

Related guides: Three Seas, One Coastline, The 2019 Türkiye–Libya Maritime Memorandum, Cyprus on the Strategic Line, Regional Order: Fact Check: Common Claims About Türkiye in International Media, Checked Against Primary Sources and Editorial Principles: Sourcing, Attribution and How We Separate Fact from Position.

Perspective note: The Strategic Meridian presents global affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources. Claims are attributed to primary sources such as treaties, UN documents and court decisions, and readers are encouraged to consult them directly. Published by The Strategic Meridian Editorial Team.