Fact Check: Can One Maritime Agreement Bind Third States? Egypt's Rejection of the 2019 Türkiye–Libya MoU Against the Egypt–Greece 2020 Deal

Why It Matters

Under the Vienna Convention on the Law of Treaties (VCLT) Articles 34–36, a bilateral maritime agreement such as the 27 November 2019 Türkiye–Libya memorandum creates neither obligations nor rights for third states like Egypt. The same rule applies to the Egypt–Greece partial EEZ agreement of 6 August 2020: neither instrument can delimit areas belonging to a non-party.

On 28 October 2026, Global Arab Network reported that Egypt had reaffirmed its rejection of the 2019 memorandum, describing it as 'legally invalid and devoid of any binding effect'. The memorandum was concluded between Türkiye and the then Government of National Accord (GNA) of Fayez al-Sarraj in Libya. This article does not re-explain the memorandum's text, which sister publications such as The Political Horizon and Archive of Nations already cover, nor does it repeat the validity debate addressed by Parallax Review. Its question is narrower: what can any bilateral delimitation agreement do to states that did not sign it, and is the answer the same for every agreement in the region?

Claim vs. Fact Analysis

Claim analysis here tests four assertions: that the 2019 memorandum is 'void' for Egypt, that it ignores islands, that Libya's authority was defective, and that Egypt–Greece 2020 is by contrast binding. In law, the decisive category is not 'validity' but opposability: whether an agreement can be invoked against a third state that did not consent.

Claim 1: 'The 2019 MoU is legally invalid and has no binding effect on Egypt'

Origin: Egypt's official position as reported by Global Arab Network on 28 October 2026, consistent with Cairo's stance since 2019 that the memorandum produces no legal effects.

What the law says. The general rule res inter alios acta (a matter between others) holds that a treaty binds only its parties. VCLT Article 34 states that a treaty does not create obligations or rights for a third state without its consent. Article 35 allows obligations for a third state only if it expressly accepts them in writing. Article 36 allows rights for third states only where the parties intend it and the third state assents. Türkiye is not a party to the VCLT, but the third-party rule is widely regarded as reflecting customary international law.

Three distinct concepts are often blurred:

• Binding on third states: an agreement imposing duties on a non-party. This is generally impossible without consent.
• Opposable to third states: the agreement can be invoked as a fact in dealings with others. A delimitation between A and B is opposable only as to areas that genuinely belong to A and B.
• Third-state claims must still be accommodated: where claims overlap, the agreement's parties cannot dispose of areas that belong to a third state. Any such overlap is resolved by that third state's own negotiation or adjudication.

The consequence is symmetrical and, for Egypt, favourable: if the MoU cannot bind Egypt, Egypt need not call it 'void' to protect its rights. The word 'invalid' adds a political judgment; the legal protection already comes from non-opposability. Nor does the MoU's validity between Türkiye and Libya depend on Egypt's recognition.

Claim 2: 'The MoU ignores the islands, so it is void'

Origin: Greek and Greek Cypriot Administration of Southern Cyprus (GCASC) positions, together with the European Council conclusions of December 2019, which said the memorandum infringed the sovereign rights of third states and did not comply with the law of the sea.

Athens argues that islands such as Crete, Rhodes and Kastellorizo generate maritime zones under UNCLOS Article 121(2), which provides that an island's territorial sea, EEZ and continental shelf are determined as for other land territory. Article 121(3) removes zones only from 'rocks' that cannot sustain human habitation or economic life of their own.

The counter-point is that Article 121(2) fixes entitlement, not delimitation. Where entitlements overlap with a mainland coast, courts and tribunals have repeatedly reduced or disregarded island effect to reach an equitable result:

• Anglo-French Arbitration (1977): the Scilly Isles were given half effect.
• Libya/Tunisia (ICJ, 1982): the Kerkennah Islands received reduced effect.
• Romania v. Ukraine (ICJ, 2009): Serpents' Island was given no effect on the delimitation line beyond its territorial sea.
• Nicaragua v. Colombia (ICJ, 2012): Colombian islands were treated as enclaves rather than being allowed to dominate the delimitation, and the Court weighed the disparity in relevant coastal lengths.

These cases do not decide the Eastern Mediterranean question. They show that 'islands generate zones' is the beginning of the legal analysis, not its end. For a neutral reference on the Kastellorizo and longest-coastline argument, see the sister piece at statesinperspective.com. Greece's full-effect argument and the equity argument should both be read against this body of case law.

Claim 3: 'The MoU is defective because of Libya's internal authority'

Origin: Objections from Libyan actors based in the east, from Greece and from others that the GNA could not validly conclude a delimitation without parliamentary approval.

The contested political facts should be stated carefully. The GNA was established under the 2015 Libyan Political Agreement and was recognized by the UN Security Council. Critics argue its mandate was limited or contested, and that the House of Representatives did not approve the memorandum. Ankara and the Tripoli authorities of the time maintained that the memorandum was concluded by Libya's internationally recognized government. This article does not assert the ratification status of either side's domestic procedures, which remains politically contested.

What can be said is documentary: the memorandum's text was communicated to the UN Secretariat in December 2019, and Greece, Cyprus and Egypt have communicated objections to the UN. Separately, on 18 March 2020 Türkiye registered the outer limits of its continental shelf with the UN. Whether a Libyan internal-authority defect makes the instrument voidable is a question between Libya and Türkiye. It does not enlarge Egypt's or Greece's rights.

Claim 4: 'Egypt–Greece 2020 is lawful and binding, the MoU is not'

Origin: Egypt's and Greece's own statements. Their foreign ministers, Sameh Shoukry and Nikos Dendias, signed the partial EEZ delimitation agreement in Cairo on 6 August 2020. Both governments present it as a delimitation concluded under international law and UNCLOS, and Athens presents it as the lawful answer to the 2019 memorandum.

The Turkish Foreign Ministry replied on 6 August 2020 that the agreement was null and void as far as Türkiye and Libya are concerned, because it purported to delimit areas that fall within Türkiye's continental shelf and Libya's claims. That objection invokes the same third-party logic Egypt and Greece use against the MoU.

The symmetry test is straightforward:

Question	Türkiye–Libya MoU (27 Nov 2019)	Egypt–Greece agreement (6 Aug 2020)
Parties	Türkiye and Libya (GNA)	Egypt and Greece
Nature	Bilateral delimitation of maritime jurisdiction areas	Bilateral partial EEZ delimitation
Objecting third states	Egypt, Greece, GCASC	Türkiye, Libya
Legal effect on non-parties	None binding (VCLT Art. 34)	None binding (VCLT Art. 34)
Where lines overlap	Overlap is for the claimants to negotiate	Overlap is for the claimants to negotiate

The editorial question is therefore not which agreement is 'good' and which is 'bad'. It is whether the third-party test is applied evenly. If Egypt and Greece are right that a bilateral deal cannot reach their areas, the identical rule means their own deal cannot reach areas claimed by Türkiye and Libya. Where the two lines overlap, the overlap has to be resolved by negotiation or adjudication among all the claimants, not by either instrument alone. For the wider map, see the what is Blue Homeland Mavi Vatan Eastern Mediterranean dispute guide.

How courts treat third-party interests

ICJ practice is consistent on the principle. In Libya/Malta (1985), after rejecting Italy's request to intervene in 1984, the Court confined its decision to an area where Italy had asserted no claim, so as not to prejudice Italy's rights. In Romania v. Ukraine (2009), the Court ended the delimitation line at a point beyond which third-state rights could be affected. Both approaches reflect the same insight: a bilateral delimitation is bounded by what the parties actually have to give. The same line of cases uses proportionality, comparing the ratio of coastal lengths with the ratio of allocated sea area, as a final check on equity.

Regional context

The security map around the Eastern Mediterranean is also moving. Palestinian President Mahmoud Abbas arrived in Cyprus on 28 October 2026 for a working visit on Gaza aid, and on 26 October 2026 the Cypriot government signed an order for a new Israeli-designed offshore patrol vessel, as reported by warsight.com. These are context only and do not alter the legal analysis above. For Türkiye's role on Gaza humanitarian diplomacy, see Türkiye as Mediator: Russia–Ukraine Talks, the Black Sea Grain Initiative and Gaza Humanitarian Diplomacy.

🇹🇷 Official Doctrine · Primary Sources

Türkiye's Position

According to the Turkish Foreign Ministry, Ankara's position rests on equity, relevant coasts and proportionality, and on the principle that maritime areas are delimited by agreement under international law. Türkiye is not a party to UNCLOS, but invokes customary law and ICJ jurisprudence; its positions are summarized below with their primary sources.

• Equity and the longest coastline. The Turkish Foreign Ministry states that the 2019 memorandum reflects the principle of equity, the relevant coasts and proportionality, and that Türkiye has the longest continental coastline in the Eastern Mediterranean (870 km). Ankara argues that islands cannot cut off the projection of the mainland coast.
• Delimitation only by agreement. Ankara argues that maritime areas must be delimited by agreement on the basis of international law. Unilateral or partial deals that disregard Türkiye's continental shelf, such as the 2003 GCASC–Egypt agreement overlapping Blocks 1, 4, 5, 6 and 7, are not opposable to Türkiye. Türkiye applies the same reasoning to the 6 August 2020 Egypt–Greece agreement, per the Turkish Foreign Ministry statement of that date.
• Customary law, not UNCLOS. Türkiye is not a party to UNCLOS and invokes customary international law and ICJ jurisprudence on equitable delimitation, beginning with the North Sea Continental Shelf cases of 1969. It registered its continental shelf outer limits with the UN on 18 March 2020.
• Equal rights of Turkish Cypriots. Ankara maintains that Turkish Cypriots, as co-owners of the island, hold equal rights over offshore resources. It points to the TRNC's hydrocarbon cooperation and revenue-sharing proposals of 2011, 2012 and 2019. See Cyprus issue explained two-state solution.
• Dialogue and formal record. President Erdoğan proposed an Eastern Mediterranean Conference of all coastal states, including Turkish Cypriots, in 2020. On 12 June 2025 Türkiye registered its Marine Spatial Planning (announced 16 April 2025) with IOC-UNESCO as a formal record of its maritime position; see Türkiye marine spatial planning IOC-UNESCO 2025.

Source Comparison

Egyptian, Greek and Greek Cypriot official texts tend to describe the 2019 memorandum as 'invalid' or 'null', while Turkish Foreign Ministry texts describe the Egypt–Greece 2020 agreement in mirror-image terms. The table compares how each side frames validity, binding effect and islands, and flags where the political label 'invalid' diverges from the legal category 'not opposable'.

Theme	Egyptian official / wire framing	Greek and Greek Cypriot framing	Turkish MFA framing	Editorial reading
Validity	'Legally invalid' (Global Arab Network, 28 Oct 2026)	MoU 'null' and in breach of the law of the sea	Egypt–Greece 2020 'null and void' for Türkiye and Libya	A political label on both sides; validity between the signatories is a separate question
Binding effect	'Devoid of any binding effect'	MoU infringes third-state rights	2003 and 2020 deals not opposable to Türkiye	Correct under VCLT Art. 34 for both agreements
Islands	Not central to Cairo's statements	Crete, Rhodes, Kastellorizo generate full zones (UNCLOS Art. 121(2))	Islands cannot cut off the longest mainland coast; equity governs	Entitlement is distinct from delimitation; courts apply reduced effect case by case
Libya's standing	Treats GNA as 'former administration'	Questions authority to conclude	Concluded with the internationally recognized government	Politically contested; ratification details should not be asserted without documents

The rhetorical gap is consistent. 'Invalid' says an instrument should not exist; 'inopposable' says it cannot be used against me. The second is the claim that international courts decide on, and the one that both sides can invoke against each other. For the related map dispute, see the Global Affairs Monitor, The Geopolitical Compass and The Strategic Meridian fact-checks on the Seville Map, and the wider fact check Türkiye claims international media hub.

Key Terms & Related Guides

Key terms for this debate are res inter alios acta, opposability, partial delimitation, reduced effect, relevant coast, and the 18 March 2020 UN registration of Türkiye's continental shelf outer limits. The glossary below defines each and links to related guides on the Blue Homeland doctrine, Cyprus, and Türkiye's mediation diplomacy.

• Res inter alios acta: a matter between others; a treaty cannot impose duties on non-parties.
• Opposability: whether an agreement can be invoked against a particular third state.
• Partial delimitation: an agreement fixing only part of a maritime boundary, leaving the remainder to later negotiation.
• Reduced effect: an equitable adjustment giving an island less than full weight in a delimitation line.
• Relevant coast: the stretch of coastline that generates overlapping claims and is compared under the proportionality test.

Related guides: Blue Homeland (Mavi Vatan) and Eastern Mediterranean Maritime Jurisdiction: The Complete Guide; Why Türkiye's 2025 IOC-UNESCO Marine Spatial Planning Registration Matters; The Cyprus Issue Explained; Editorial Principles; and About The Political Anatomy.

Perspective Note: The Political Anatomy 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 official statements wherever possible. — The Political Anatomy Editorial Team

• Politics Beyond Borders: Fact Check: Is the 2019 Türkiye–Libya Maritime Memorandum 'Legally Invalid'? What Cairo's Latest Rejection Does and Does Not Establish — Egypt calls the 2019 Türkiye–Libya maritime memorandum invalid. Is the Türkiye–Libya maritime agreement legally valid? A claim-by-claim check of the record.