Historical and Legal Background

_ 1. Treaty of Lausanne — 1923
_ 2. Convention of Lausanne on the Straits — 1923
_ 3. Montreux Convention — 1936
_ 4. Treaty of Peace with Italy (Paris Peace Treaty) — 1947
_ 5. UN Charter — particularly Article 51

The Treaty of Lausanne (1923) established the post-Ottoman territorial settlement, confirming Greek sovereignty over the major eastern Aegean islands. However, the treaty did not apply a uniform military regime across all of these territories. For islands like Lesbos, Chios, Samos, and Ikaria, Article 13 implemented specific military restrictions—such as banning naval bases and fortifications—rather than a total ban on forces. Greece argues that this distinction makes the blanket term "demilitarisation" legally misleading, as these specific restrictions do not equate to a strict, absolute demilitarised regime.

A more complex dispute involves Lemnos and Samothrace, which were originally demilitarised under the separate 1923 Straits Convention. This arrangement changed when the parties signed the Montreux Convention of 1936, which officially replaced the 1923 pact. Greece maintains that because Montreux superseded the old convention, the demilitarisation clauses for Lemnos and Samothrace ceased to exist. Conversely, Turkey argues that the Montreux Convention dealt strictly with shipping and navigation, meaning the original demilitarisation obligations for the islands remain fully intact.

Historical evidence from 1936 strongly supports the Greek interpretation, showing that the Turkish government initially recognized Greece's right to militarize Lemnos and Samothrace. The Turkish Foreign Minister at the time even made formal statements to the Turkish Parliament acknowledging this shift after the Montreux Convention took effect. Over time, Turkey shifted away from this stance, leading to a fundamental and ongoing diplomatic disagreement between the two nations regarding the true legal intent of the 1936 treaty.

The Dodecanese islands fall under a completely different legal category because Turkey initially ceded them to Italy, which held them until the end of World War II. Under Article 14 of the Paris Peace Treaty of 1947, Italy transferred these islands to Greece with the explicit condition that they "shall remain demilitarised." Turkey relies on this unambiguous clause to argue that any modern Greek military presence in the Dodecanese violates international law, creating a distinct legal challenge from the arguments surrounding the Lausanne and Montreux treaties.

The 1947 Paris Peace Treaty introduces a critical international law debate regarding whether a non-signatory state can enforce treaty terms. Because Turkey was not a party to the 1947 pact between Italy and the Allies, Greece invokes Article 34 of the Vienna Convention on the Law of Treaties, arguing a treaty cannot impose obligations on a third party without its consent. However, a major counterargument persists in international law: certain territorial agreements establish an "objective regime" attached directly to the land, which can legally bind the sovereign nation regardless of who signed the original document.

Beyond specific treaty text, the United Nations Charter (1945) dramatically altered the legal landscape of state sovereignty and national security. Under Article 51, every nation possesses an "inherent right of individual or collective self-defence" against military threats. Greece maintains that outdated demilitarisation clauses cannot force a nation to leave strategically vital territories undefended. Conversely, Turkey counters that Article 51 is not a blanket justification to permanently bypass binding international pacted obligations absent an actual, ongoing armed attack

This legal dispute is heavily intensified by modern security dynamics, most notably the 1995 casus belli declared by the Turkish Grand National Assembly. Turkey decreed that if Greece exercised its right to extend its territorial waters to 12 nautical miles, it would be considered a declaration of war. Greece presents this overt military threat as definitive justification that it cannot leave its Aegean islands undefended, while Turkey firmly maintains that these political tensions do not absolve Greece from its underlying, binding legal commitments.

Ultimately, the friction stems from differing interpretations of "demilitarisation" across an island-by-island framework. While Dodecanese islands like Rhodes and Kastellorizo face explicit demilitarisation from 1947, islands like Lesbos and Chios fall under Lausanne's specific restrictions, and Lemnos and Samothrace are claimed by Greece to be entirely freed from restrictions by the 1936 Montreux Convention. This spectrum of complete demilitarisation, limited forces, and narrow technical bans ensures that the Aegean remains a deeply contested legal theater between both nations.

What is not disputed

There are several points that should be separated from the political dispute.

Greek sovereignty over these islands Turkey does not simply have a treaty-based right to take the islands because they are allegedly demilitarised. Demilitarisation and sovereignty are different legal questions. A treaty can provide: "State A owns the territory, but the territory must remain demilitarised." That does not mean: "State B owns the territory." This distinction is fundamental.

The International Court of Justice

The issue has never been definitively resolved by a judgment of the International Court of Justice declaring either: "Greece is entitled to militarise all these islands" or "Turkey is correct that all these islands must be demilitarised." Greece and Turkey have had several disputes concerning the Aegean. The 1976 Aegean Sea Continental Shelf case reached the International Court of Justice, but the Court ultimately found that it lacked jurisdiction to decide the merits on the basis relied upon by Greece. Consequently, there is no definitive ICJ judgment settling the entire Aegean demilitarisation dispute.

The key legal distinction

The most accurate way of describing the situation is therefore:
Lemnos and Samothrace
The principal Greek argument is based on Montreux 1936.
Lesbos, Chios, Samos and Ikaria
The Treaty of Lausanne imposes specific restrictions, rather than simply saying that the islands must contain no military forces whatsoever.
Dodecanese
The 1947 Paris Peace Treaty contains an express demilitarisation clause.
Kastellorizo
It falls within the Dodecanese settlement and therefore comes under the 1947 regime.

The central legal dispute

1. What exactly did Lausanne prohibit?
2. Did Montreux terminate the demilitarisation regime applicable to Lemnos and Samothrace?
3. What is the legal effect of Article 14 of the 1947 Paris Treaty?
4. Can Turkey invoke a treaty to which it is not a party?
5. Can Greece rely upon the inherent right of self-defence to justify military measures on islands subject to demilitarisation obligations?
6. Does subsequent international law, particularly the UN Charter, affect the interpretation or operation of these older treaty provisions?