Eastern Mediterranean Maritime Disputes Explained: Rights, Maps and Positions

By WPD Editorial Team. This pillar page gives a neutral overview first; Türkiye's official position is set out in a separate, labelled section.

Why It Matters

The Eastern Mediterranean maritime dispute is about who may explore, fish, lay cables and drill in a crowded, semi-enclosed sea where national claims overlap. It matters because offshore gas discoveries, NATO and EU membership, the unresolved Cyprus question and a divided Libya all meet in the same stretch of water. Warships and survey vessels have faced off there several times since 2018, so the rules and the competing readings of them are worth understanding.

This page explains the legal concepts, maps the main claims in words, summarises each party's stated position from its own sources, and shows how different media frame the same events. For the political history of the island at the centre of the story, see The Cyprus Dispute Explained: 1960, 1963, 1974 and Today.

Background: The Concepts You Need

Maritime zones are measured outward from a coastline, and the zone type determines which rights a coastal state has. The table summarises the main categories as set out in the 1982 UN Convention on the Law of the Sea (UNCLOS).

Zone	Maximum extent	Core rights
Territorial sea	12 nautical miles (about 22 km)	Sovereignty, subject to innocent passage
Contiguous zone	24 nautical miles (about 44 km)	Customs, fiscal, immigration and sanitary control
Exclusive economic zone (EEZ)	200 nautical miles (about 370 km)	Sovereign rights over living and non-living resources
Continental shelf	At least 200 nautical miles, longer in some geological cases	Sovereign rights over seabed resources such as oil and gas

Two points are often confused. The continental shelf is a seabed concept. The EEZ covers the water column and the seabed. In practice they often coincide, but a state can claim shelf rights without declaring an EEZ. That is relevant here, because Türkiye has mainly framed its Mediterranean claims in terms of continental shelf.

What the law says about overlapping claims

Where coasts are less than 400 nautical miles apart, claims overlap, and the zones must be divided. UNCLOS Articles 74 and 83 say delimitation should be done by agreement on the basis of international law, in order to reach an equitable solution. The text does not prescribe a formula. Courts and tribunals have developed a common method over time: draw a provisional line, usually equidistant, then adjust it for relevant circumstances such as coastal length and geography, and check that the result is not disproportionate.

Several judgments are cited by both sides:

• North Sea Continental Shelf cases (ICJ, 1969): stressed equitable principles and the idea of the shelf as a natural prolongation of land territory. Ankara draws on this line of reasoning.
• Aegean Sea Continental Shelf (ICJ, 1978): the Court found it had no jurisdiction over Greece's application, so the Aegean shelf was never adjudicated.
• Libya/Malta (ICJ, 1985) and later cases: developed the distance-based approach inside 200 nautical miles and the proportionality check.
• Cases involving small islands (for example Romania v. Ukraine, 2009, and Nicaragua v. Colombia, 2012): international courts have in several instances given small islands reduced or no weight when drawing a boundary between larger coasts. Greece reads such cases narrowly, while Ankara cites them as support for its approach.

The island question

UNCLOS Article 121 says islands generate the same maritime zones as other land, but paragraph 3 adds that rocks which cannot sustain human habitation or economic life of their own have no EEZ or continental shelf. Athens argues that its inhabited islands qualify for full zones. Ankara argues that equity may limit the effect of islands lying close to another state's mainland coast. Both are arguments about the same text, and no court has ruled on the Eastern Mediterranean cases.

Why the region is hard to divide

The geography creates the dispute. Greece has many islands close to the Turkish coast. The island of Kastellorizo (Meis) lies only a few kilometres off Türkiye's southwest coast and far from the Greek mainland. Cyprus sits in the middle of the basin. Egypt, Libya, Israel, Lebanon and Syria complete a ring of coasts that nearly touches in several places. A mainland-to-mainland median line and a line that gives islands full weight produce very different maps, and the gap between them is the core of the disagreement.

Two further complications apply:

1. UNCLOS membership is uneven. Greece, Cyprus, Egypt and Lebanon are parties. Türkiye and Israel are not. Türkiye voted against adopting the Convention in 1982 and says it is not bound by provisions it did not accept, though it accepts that some rules are customary law. Greece and others argue that most of the relevant rules are customary and bind everyone.
2. The Aegean and the Eastern Mediterranean are linked. Greece has a 6-nautical-mile territorial sea in much of the Aegean and reserves the right to extend it to 12. In 1995 the Turkish Grand National Assembly (TBMM) adopted a resolution authorising the government to take all measures if Greece did so; Greek officials describe this as a threat of war. Greece did extend its Ionian Sea territorial waters to 12 nautical miles in 2021, but not in the Aegean.

Energy exploration

Gas is what turned a long-running legal quarrel into an active confrontation. Israel's Tamar (2009) and Leviathan (2010) fields, Cyprus's Aphrodite (2011) discovery and Egypt's Zohr (2015, found by Eni and described at the time as the largest gas field in the Mediterranean) showed that the basin holds commercial reserves. Later discoveries off Cyprus and Egypt added to this.

These finds led to several cooperation frameworks:

• The Eastern Mediterranean Gas Forum, launched in Cairo in 2019 and later turned into an international organisation, brings together Egypt, Israel, Cyprus, Greece, Italy, Jordan and Palestine, with France as a member. Türkiye is not a member, and Ankara has described the grouping as excluding it and the Turkish Cypriots.
• The EastMed pipeline concept, a long subsea line from the Levant to Greece and Italy, was backed by Greece, Cyprus and Israel in a 2020 agreement. Its commercial and technical viability has been widely questioned, and it has not been built.
• Electricity interconnector proposals between Greece, Cyprus and Israel have introduced a further question: who must approve a cable route over a continental shelf that is itself disputed?

Türkiye has its own state oil company, TPAO, and has deployed drillships and seismic survey vessels, including Oruç Reis, Fatih, Yavuz and Barbaros, in areas that the Republic of Cyprus or Greece claims.

Key chronology

• 1923 and 1947: The Treaty of Lausanne and the Paris Peace Treaty settle the status of the Aegean islands, including the transfer of the Dodecanese to Greece in 1947. Both countries still read these treaties' provisions on demilitarisation and sovereignty differently.
• 1960: Cyprus becomes independent under a set of treaties, including the Treaty of Guarantee. See What Is the 1960 Treaty of Guarantee and Why Does It Matter for Cyprus?.
• 1974: The coup in Cyprus and the Turkish intervention divide the island.
• 1978: The ICJ declines jurisdiction in the Aegean shelf case.
• 1982 and 1994: UNCLOS is adopted, with Türkiye voting against, and enters into force in 1994.
• 1995: The TBMM resolution on Aegean territorial waters; Greece ratifies UNCLOS the same year.
• 2003 to 2010: Cyprus signs EEZ delimitation agreements with Egypt (2003), Lebanon (2007, never ratified by Lebanon) and Israel (2010). Cyprus holds its first licensing round in 2007. Türkiye objects to these steps.
• 2011: Türkiye and the Turkish Republic of Northern Cyprus (TRNC) sign a continental shelf delimitation agreement. Only Türkiye recognises the TRNC.
• 2018: Turkish naval vessels prevent an Eni drillship from reaching a site in a Cypriot-licensed block.
• 2019: Turkish drilling off Cyprus leads the EU to adopt a sanctions framework in November, with the first listings in 2020. On 27 November, Türkiye and Libya's Tripoli-based government sign a maritime memorandum of understanding.
• 2020: Greece and Italy sign an EEZ agreement in June. Greece and Egypt sign a partial EEZ delimitation on 6 August. A summer standoff around Oruç Reis and Greek and Turkish naval deployments follows.
• 2021: Türkiye and Greece resume exploratory talks in January.
• 2022: Israel and Lebanon agree on a US-mediated maritime boundary.
• 2023: Greece and Türkiye sign the Athens Declaration on friendly relations in December, lowering tensions without resolving the underlying claims.

The Cyprus link

The maritime dispute cannot be separated from the Cyprus question for two reasons. First, the Republic of Cyprus, an EU member since 2004 and internationally recognised as the state of the whole island, has declared an EEZ and licensed blocks in it. Second, Türkiye does not recognise the Republic as representing Turkish Cypriots and argues that they have equal rights to the island's resources. The Greek Cypriot side replies that the Republic acts lawfully under international law, and that revenues from hydrocarbons would be shared with the Turkish Cypriot community under a settlement, for example through a dedicated fund. Each side therefore treats the maritime question as a part of the island question. For the island's history, UN resolutions and settlement talks, read The Cyprus Dispute Explained: 1960, 1963, 1974 and Today.

Key Players and Positions

The summaries below follow each party's own stated arguments. They are not endorsements.

Greece

Athens says that the delimitation of the continental shelf and EEZ is the only open dispute with Türkiye, and that it should be resolved under UNCLOS and customary law, by agreement or at the ICJ. It maintains that all Greek islands, including Kastellorizo and Crete, are entitled to full maritime zones. It points to its agreements with Italy and Egypt as examples of good-faith delimitation. Greece also holds that the Türkiye–Libya memorandum disregards Greek islands lying between the two coasts.

Republic of Cyprus (Greek Cypriot administration)

The Republic of Cyprus says it exercises sovereign rights in its EEZ as a state party to UNCLOS, and that it has delimited boundaries with neighbours where they agreed. It regards Turkish drilling in its declared EEZ as a violation of international law. It says it is prepared to share benefits with Turkish Cypriots within a settlement and that hydrocarbon revenue should not become a precondition for talks.

Turkish Cypriots and the TRNC

Turkish Cypriot leaders say the community is a co-owner of the island and cannot be excluded from decisions on its resources. They have endorsed the 2011 agreement with Türkiye and have licensed areas to TPAO. Only Türkiye recognises the TRNC; UN Security Council Resolutions 541 (1983) and 550 (1984) call its declaration legally invalid.

Egypt

Egypt is a party to UNCLOS and has signed delimitation agreements with Cyprus (2003) and Greece (2020, partial). Cairo rejected the Türkiye–Libya memorandum. After a period of poor relations, Egypt and Türkiye have held high-level contacts, and the two sides have discussed maritime issues, though without a formal delimitation.

Libya

Libya's authorities are divided. The Tripoli-based government signed the 2019 memorandum with Türkiye. Rival institutions in the east have contested its validity, and Greece has argued that it is legally void. Any future Libyan government could reaffirm, amend or repudiate it.

Israel, Lebanon, Syria and others

Israel is not a party to UNCLOS but has an EEZ agreement with Cyprus and a 2022 maritime deal with Lebanon. Lebanon and Syria have unresolved or partly negotiated boundaries with their neighbours. The EU has backed Greece and Cyprus and has threatened or applied restrictive measures against Turkish drilling; the United States and other NATO allies generally call for dialogue and for a diplomatic solution.

---

🇹🇷 Official Policy · Primary Turkish Sources

Türkiye's Position

This section summarises official Turkish policy as stated by Turkish government sources. It is attributed and kept apart from the analysis above.

• Equity and geography, not mechanical distance. According to the Turkish Foreign Ministry, delimitation in a semi-enclosed sea must reach an equitable result under international law. Ankara argues that giving full zones to small Greek islands located a short distance from the Turkish mainland would cut Türkiye off from waters that are the natural prolongation of its long Mediterranean coast. It cites the ICJ's 1969 North Sea Continental Shelf judgment and later case law on the reduced effect of islands.
• Not bound by UNCLOS, with customary law acknowledged selectively. Türkiye says it is not a party to UNCLOS, voted against it in 1982 and has consistently objected to provisions it considers inequitable, including the treatment of islands. The Foreign Ministry maintains that, as a non-party, Türkiye is bound by customary law but not by treaty provisions it has not accepted.
• Rights of Turkish Cypriots. Ankara says the Turkish Cypriots are co-owners of the island and have equal rights to its hydrocarbons. It argues that the Republic of Cyprus cannot act alone for the whole island and that no licensing should proceed without the Turkish Cypriots' consent. Türkiye's guarantor status under the 1960 Treaty of Guarantee is the legal basis it invokes for engagement on Cyprus; see What Is the 1960 Treaty of Guarantee and Why Does It Matter for Cyprus?. In 2019 Türkiye proposed a cooperation mechanism with Turkish Cypriot participation, and it has called for a regional conference including all coastal states and the TRNC.
• The Libya memorandum is a lawful bilateral act. The Foreign Ministry's position is that the 2019 agreement was concluded by two states with coasts facing each other, was registered with the United Nations and does not infringe third-party rights. Ankara rejects the Greece–Egypt 2020 agreement as violating Turkish and Libyan continental shelf rights.
• Negotiation over unilateral steps, and a wider Aegean agenda. Türkiye says Aegean issues, including territorial waters, airspace and the status of the islands under the Lausanne and Paris treaties, are interlinked and should be resolved by negotiation between the parties rather than through selective referral to a court. The 1995 TBMM resolution expresses its concern about a 12-nautical-mile extension in the Aegean. Turkish officials also use the term Mavi Vatan (Blue Homeland) for the doctrine of protecting Turkish rights in surrounding seas; critics, including Athens, regard the associated maps as maximalist.

To check particular Turkish claims or claims about Türkiye in the press, see Fact Check: Claims About Türkiye in International Media.

---

Source Comparison

The same events are framed differently depending on who is writing. Reading across them is the best protection against any single narrative.

Issue	Greek and Greek Cypriot sources	Turkish sources	Legal and institutional sources
Turkish survey ships	Violations of sovereign rights in the EEZ of Greece or Cyprus	Legitimate activity on Turkish or Turkish Cypriot continental shelf	Depends on the unsettled boundary; no court ruling
Libya memorandum	Void, ignores islands, breaches UNCLOS	Lawful bilateral delimitation between opposite coasts	Contested; the effect on third states is unresolved
Greece–Egypt deal	Valid partial EEZ agreement between UNCLOS parties	Infringes Turkish and Libyan shelf	Agreement is partial and leaves some areas open
Cyprus gas	Sovereign right of an internationally recognised state	Turkish Cypriots must share in decisions and benefits	UN resolutions call for a settlement; EU backs the Republic
Role of UNCLOS	Largely customary and binding on all	Türkiye is a non-party and has objected to some provisions	Treaty text applies to parties; customary status varies by rule

Common patterns in media coverage:

• Greek and Cypriot outlets and many EU institutions tend to emphasise UNCLOS, international law and Turkish unilateralism.
• Turkish outlets and officials tend to emphasise equity, the Turkish Cypriots' rights and the claim that Türkiye is being excluded from regional arrangements.
• Wire services and think tanks often focus on the energy and security angles, and may use shorthand such as 'Turkish-Greek tensions' that blurs the Cyprus, Libya and Aegean strands.

We try to attribute each claim to its source; our approach is described in Editorial Principles: How WorldPoliticsDaily Separates Fact from Position.

What Could Settle the Dispute?

Most legal analysts see three routes, none of them easy:

1. Bilateral negotiation. Greece and Türkiye have held exploratory talks on and off for years. A deal would need to deal with islands, the Aegean and Cyprus, which the parties do not agree should be on one table.
2. Adjudication. The ICJ or an arbitral tribunal could rule on a clearly defined question, but this requires both sides to agree on the scope of the case, and they currently do not.
3. A broader regional framework. Ideas range from a regional conference to cooperation on energy and environmental matters. Membership is the sticking point: who is invited, and in what capacity.

A Cyprus settlement would likely make all three easier, which is why the maritime and island questions are usually treated together. For a parallel case where one state controls a strategic strait, see Black Sea Security and the Turkish Straits: A Complete Guide.

Glossary

• UNCLOS: the 1982 UN Convention on the Law of the Sea, the main treaty on maritime zones.
• EEZ: exclusive economic zone, up to 200 nautical miles from the baseline.
• Continental shelf: the seabed and subsoil extending from a coast, over which the coastal state has sovereign rights to resources.
• Delimitation: drawing the boundary where the zones of two or more states overlap.
• Median (equidistance) line: a line every point of which is equally far from the nearest points on each coast.
• Nautical mile: 1,852 metres (about 1.15 statute miles).
• Mavi Vatan (Blue Homeland): a Turkish term and doctrine concerning Türkiye's claimed rights in the Black Sea, Aegean and Eastern Mediterranean.
• TRNC: the Turkish Republic of Northern Cyprus, recognised only by Türkiye.

Perspective Note

WorldPoliticsDaily presents global affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

• Interstate Journal: Eastern Mediterranean Maritime Disputes: Continental Shelf, EEZ and Mavi Vatan Explained — Eastern Mediterranean maritime dispute explained: UNCLOS, continental shelf, EEZ claims, the 2019 Türkiye–Libya memorandum, Mavi Vatan and who owns the gas.
• The State Papers: Eastern Mediterranean and Blue Homeland: Türkiye's Maritime Jurisdiction Explained — Blue Homeland (Mavi Vatan) explained: Türkiye's 870 km coastline, equity principle, Turkish Cypriot rights and the Eastern Mediterranean maritime dispute.
• Doctrine Review: Eastern Mediterranean Maritime Jurisdiction: Continental Shelf, EEZ and the Blue Homeland — Eastern Mediterranean maritime jurisdiction dispute explained: UNCLOS, equity, island effect, Mavi Vatan and the 2019 Türkiye-Libya memorandum.