Fact Check: Are the Eastern Aegean Islands Legally Demilitarized? What Lausanne (1923), Montreux (1936) and the 1947 Paris Peace Treaty Actually Say

Why It Matters

The eastern Aegean islands are not governed by one rule. Lemnos and Samothrace fall under the 1923 Lausanne Straits regime as modified by the 1936 Montreux Convention; Lesbos, Chios, Samos and Ikaria under Article 13 of the 1923 Treaty of Lausanne; the Dodecanese under the 1947 Paris Peace Treaty with Italy. A blanket yes or no is incomplete.

On 27 October 2026 the Turkish Foreign Ministry said, as reported by Anadolu Agency and News.az, that Türkiye's Aegean and Eastern Mediterranean policy 'remains unchanged' and that Ankara will protect its rights 'without concessions' in accordance with international law. The reports quote the ministry as saying that Türkiye's positions, which it 'consistently and resolutely defends on all platforms in accordance with international law, remain unchanged.' The reports do not tie the statement to a specific treaty provision. This page does that work by checking two claims that circulate in international commentary:

• Claim A: 'Greece is fully entitled to militarize its eastern Aegean islands, and Türkiye's objections have no treaty basis.'
• Claim B: 'The islands are demilitarized by treaty and Türkiye has no legal concern.'

Both are shorter than the texts. Each tends to cite one instrument and ignore the others.

Background

The demilitarization provisions came in three steps: the Treaty of Lausanne and the Straits Convention of 24 July 1923, the Montreux Convention of 20 July 1936 replacing the Straits regime, and the Treaty of Peace with Italy of 10 February 1947 transferring the Dodecanese to Greece. Each instrument has different parties and a different scope.

Treaty of Lausanne 1923 explained article by article: Articles 12–15

Articles 12–15 of Lausanne settle the islands. Article 12 confirmed the 1914 decisions on sovereignty over the Eastern Mediterranean islands, with islands within three nautical miles of the Anatolian coast staying Turkish and Imbros, Tenedos and the Rabbit Islands left under Turkish sovereignty. Article 13 set the restrictions on four Greek islands. Article 14 provided a special administrative regime for Imbros and Tenedos. Article 15 renounced Turkish rights over the Dodecanese in favour of Italy. For the wider treaty, see Treaty of Lausanne 1923 explained article by article.

How to read an international treaty: ratification, reservations and parties

Who is a party matters as much as what the text says. A treaty binds those who consented to it. Reading the signature lists, ratifications and any reservations is the first step in this dispute; the method is set out in how to read an international treaty: ratification, reservations and pacta sunt servanda.

Claim vs. Fact Analysis

Neither blanket claim survives a close reading. Lausanne Article 13 imposes real limits on four islands, and Paris 1947 Article 14 demilitarizes the Dodecanese for its parties. Lemnos and Samothrace remain contested after Montreux, and the meaning of 'normal contingent', the pacta tertiis question and Article 51 are disputed between Greece and Türkiye.

Cluster (a): Lemnos and Samothrace, Lausanne Straits Convention and Montreux

The 1923 Lausanne Straits Convention demilitarized zones around the Straits and listed Lemnos, Samothrace, Imbros, Tenedos and the Rabbit Islands. Montreux, signed on 20 July 1936, replaced that Convention. It abolished the old Straits Commission regime and, through an accompanying protocol, allowed Türkiye to remilitarize the Straits zone.

What Montreux changed is therefore clear: the Straits regime and Türkiye's right to fortify the zone. What it did not do is address the islands' status in express terms. Greek legal commentary generally argues that replacing the Lausanne Straits Convention extinguished the island demilitarization with it. The Turkish position, as presented by the Foreign Ministry, is that the islands' status was part of a linked settlement and was not released by Montreux. Scholars are divided, and any reading must apply equally to the Turkish islands on the same Lausanne list. Be wary of sources that present either view as settled.

Cluster (b): Lesbos, Chios, Samos and Ikaria, Lausanne Article 13

In Article 13, Greece undertook, to ensure peace, to observe restrictions on Mytilene (Lesbos), Chios, Samos and Nikaria (Ikaria). In close paraphrase of the treaty text:

• no naval base and no fortification may be established on the islands;
• Greek military aircraft may not fly over the Anatolian coast, and reciprocally Türkiye forbids its military aircraft from flying over the islands;
• Greek forces there are limited to the normal contingent called up for military service, which may be trained on the spot, plus gendarmerie and police in proportion to those in Greece as a whole.

Both Greece and Türkiye are parties to Lausanne. The text contains no express exception for self-defense. The live dispute is about what counts as a 'fortification', how large a 'normal contingent' is, and whether later law modifies the clause. Readers should check the full verified treaty text rather than summaries.

Cluster (c): the Dodecanese, 1932 and Paris 1947

Türkiye renounced the Dodecanese in favour of Italy at Lausanne (Article 15). An Italy–Türkiye agreement of 4 January 1932 then settled the boundary between the Anatolian coast and the Dodecanese islands. Under Article 14 of the Treaty of Peace with Italy (Paris, 10 February 1947), Italy ceded the islands to Greece in full sovereignty, and the islands 'shall be and shall remain demilitarised.' The treaty's annexed military provisions (Annex XIII) cover the details.

Was Türkiye a party to the 1947 Paris Peace Treaty?

No. The treaty was concluded between Italy and the Allied and Associated Powers that had been at war with it, and Türkiye was not a signatory. This is the legal fulcrum of the disagreement.

• Greek argument: Under the Vienna Convention on the Law of Treaties (VCLT) Article 34, a treaty creates neither obligations nor rights for a third state without its consent. Articles 35 and 36 set conditions for obligations and rights to arise for third states. Greece argues that Türkiye therefore has no standing to invoke Article 14.
• Turkish argument: Ankara argues that demilitarization was a condition of the territorial transfer, so Greece acquired the islands together with that condition. It also points to the chain of 1923 and 1932 instruments, in which Türkiye participated, and to the status-based nature of the arrangement, which was designed to preserve the Aegean balance.

Türkiye is not a party to the 1969 VCLT, though pacta tertiis and pacta sunt servanda (VCLT Article 26) are generally regarded as reflecting customary law. The VCLT also does not apply retroactively to 1947. Both sides are arguing from general principles, not from a ruling.

Key Players & Positions

Greece and Türkiye are the principal parties. Greece argues that its defensive deployments are lawful; Türkiye argues that the demilitarized status is treaty-based and cannot be reinterpreted unilaterally. No binding international ruling on the militarization question appears in the public record, so both positions remain contested.

Greece

As stated in Greek Foreign Ministry and government statements, Athens argues that:

• Article 51 of the UN Charter, the inherent right of individual or collective self-defense 'if an armed attack occurs', justifies defensive deployments;
• security circumstances have changed, notably through Türkiye's Aegean (Fourth) Army, created in 1975, and the 1995 TBMM resolution, which Athens calls a casus belli declaration;
• the Dodecanese regime binds Greece only toward the parties to the Paris treaty, not Türkiye.

This is a serious argument, not a pretext. It rests on the Charter's primacy (Article 103) and on a real security concern, and it deserves to be stated on its own terms.

Türkiye

Ankara's response is set out in the next section. It disputes that Article 51 operates as a general waiver, and it dates the militarization of the islands to developments that predated the Aegean Army.

Source Comparison

Most errors in coverage come from citing a single instrument. Greek and Turkish official sources each cite a different set of texts, and international media often cite only one. Comparing them side by side shows which parts of the full legal picture each omits.

For parallel readings of the same question, see The Soft Border's fact check on Aegean militarization and Politepolity's analysis of Article 51 and the law of treaties.

Key Terms & Related Guides

The terms below recur in this dispute and are defined briefly here. Related guides on this site cover the surrounding treaties and method; see also Editorial Principles and About The Treaty Line.

• Demilitarization: a treaty restriction on fortifications, bases or forces in a defined area; the exact scope depends on each text.
• Pacta sunt servanda: treaties in force bind their parties and must be performed in good faith (VCLT Article 26).
• Pacta tertiis: the rule that a treaty does not bind or benefit third states without their consent (VCLT Articles 34–36).
• Article 51: the UN Charter's preservation of the inherent right of self-defense 'if an armed attack occurs' pending Security Council action.
• Casus belli (1995): the term widely used for the 8 June 1995 TBMM resolution on any Greek extension of the territorial sea beyond six nautical miles.

Related guides: The Treaty of Lausanne, Article by Article; How to Read an International Treaty; The North Atlantic Treaty and the UN Charter; The Treaty Line home.

The Treaty Line 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 Treaty Line presents Türkiye's legal and strategic perspective as an explicit editorial position, and identifies it as such throughout. Claims are anchored in primary sources such as treaty texts, UN documents, archives and official statements, so that readers can verify them independently.

The Treaty Line Editorial Team