TheAegean dispute is a set of interrelated controversies betweenGreece andTurkey over sovereignty and related rights in the region of theAegean Sea. This set of conflicts has strongly affectedGreek-Turkish relations since the 1970s, and has twice led to crises coming close to the outbreak of military hostilities, in 1987 and in early 1996. The issues in the Aegean fall into several categories:

• The delimitation ofterritorial waters,
• The delimitation ofnational airspace,
• The delimitation ofexclusive economic zones (EEZ) and the use of thecontinental shelf,
• The role offlight information regions (FIR) for the control of military flight activity,
• The issue of thedemilitarized status assigned to some of theGreek islands in the region,
• Turkish claims of "grey zones" of undetermined sovereignty over a number ofislets, most notably the islets ofImia.

One aspect of the dispute is the differing interpretations of themaritime law: Turkey has not signed up to theConvention on the Continental Shelf nor the supersedingUnited Nations Convention on the Law of the Sea, which as of July 2024 has been signed by 170 parties, including Greece; as such, Turkey does not recognize a legal continental shelf and EEZ around the Greek islands.

Between 1998 and the early 2010s, the two countries came closer to overcoming the tensions through a series of diplomatic measures, particularly with a view to easingTurkey's accession to theEuropean Union. However, differences over suitable diplomatic paths to a substantial solution remained unresolved, and as of 2024 tensions remain.

Several of the Aegean issues deal with the delimitation of both countries' zones of influence in the air and on the sea around their respective territories. These issues owe their virulence to a geographical peculiarity of the Aegean sea and its territories. While the mainland coasts of Greece and Turkey bordering the Aegean Sea on both sides represent roughly equal shares of its total coastline, the overwhelming number of the manyAegean islands belong to Greece. In particular, there is a chain of Greek islands lined up along the Turkish west coast (Lesbos,Chios,Samos, and theDodecanese islands), some of them in very close proximity to the mainland. Their existence blocks Turkey from extending any of its zones of influence beyond a few nautical miles off its coastline. As the breadth of maritime and aerial zones of influence, such as the territorial waters and national airspace, are measured from the nearest territory of the state in question, including its islands, any possible extension of such zones would necessarily benefit Greece much more than Turkey proportionally.

According to a popular perception^{[clarification needed]} of these issues in the two countries, Turkey is concerned that Greece might be trying to extend its zones of influence to such a degree that it would turn the Aegean effectively into a "Greek lake". Conversely, Greece is concerned that Turkey might try to "occupy half of the Aegean", i.e. establish Turkish zones of influence towards the middle of the Aegean, beyond the chain of outlying Greek islands, turning these into a kind of exclave surrounded by Turkish waters, and thus cutting them off from their motherland.^[1]

Territorial waters give the littoral state full control over air navigation in the airspace above, and partial control over shipping, although foreign ships (both civil and military) are normally guaranteedinnocent passage through them. The standard width of territorial waters that countries are customarily entitled to has steadily increased in the course of the 20th century: from initially 3 nautical miles (5.6 km) at the beginning of the century, to 6 nautical miles (11 km), and currently 12 nautical miles (22 km). The current value has been enshrined in treaty law by theUnited Nations Convention on the Law of the Sea of 1982 (Art.3). In the Aegean, the territorial waters claimed by both sides are still at 6 miles. The possibility of an extension to 12 miles has fuelled Turkish concerns over a possible disproportionate increase in Greek-controlled space. Turkey has not become a member of the convention and does not consider itself bound by it. Turkey considers the convention asres inter alios acta, i.e. a treaty that can only be binding to the signing parties but not to others. Greece, which is a party to the convention, has stated that it reserves the right to apply this rule and extend its waters to 12 miles at some point in the future in the Aegean Sea (it has already done so in the Ionian Sea to the west). Greece holds that the 12-mile rule is not only treaty law but alsocustomary law, as per the wide consensus established among the international community. Against this, Turkey argues that the special geographical properties of the Aegean Sea make a strict application of the 12-mile rule in this case illicit in the interest ofequity.^[2] Turkey has itself applied the customary 12-mile limit to its coasts outside the Aegean.

Tensions over the 12-mile question ran highest between the two countries in the early 1990s, when the Law of the Sea was going to come into force. On 8 June 1995, the Turkish parliament officially declared that unilateral action by Greece would constitute acasus belli, i.e. reason to go to war. This declaration has been condemned by Greece as a violation of theCharter of the United Nations, which forbids "the threat or use of force against the territorial integrity or political independence of any state".^[1]

National airspace is normally defined as the airspace covering a state's land territory and its adjacent territorial waters. National airspace gives the sovereign state a large degree of control over foreign air traffic. While civil aviation is normally allowed passage under international treaties, foreign military and other state aircraft (unlike military vessels in the territorial waters) do not have a right to free passage through another state's national airspace.^[3] The delimitation of national airspace claimed by Greece is the only example in the world, as it does not coincide with the boundary of the territorial waters. Greece claims 10 nautical miles (19 km) of airspace, as opposed to currently 6 miles of territorial waters. Since 1974, Turkey has refused to acknowledge the validity of the outer 4-mile belt of airspace that extends beyond the Greek territorial waters. Turkey cites the statutes of theInternational Civil Aviation Organization(ICAO) of 1948, as containing a binding definition that both zones must coincide.^[4] Against this, Greece argues that:

• its 10-nautical-mile (19 km) claim predates the ICAO statute, having been fixed in 1931, and that it was acknowledged by all its neighbours, including Turkey, before and after 1948, hence constituting an established right;^[5]
• its 10-mile claim can also be interpreted as just a partial, selective use of the much wider rights guaranteed by the Law of the Sea, namely the right to a 12-mile zone both in the air and on the water;
• Greek territorial waters are set at the 6-mile boundary only because of Turkey'scasus belli.

The conflict over military flight activities has led to a practice of continuous tactical military provocations, with Turkish aircraft flying in the outer 4-mile zone of contentious airspace and Greek aircraft intercepting them. These encounters often lead to so-called "dog-fights", dangerous flight manoeuvres that have repeatedly ended in casualties on both sides. In one instance in 1996, it has been alleged that a Turkish plane was accidentally shot down by a Greek one.^[6]

In the context of the Aegean dispute, the termcontinental shelf refers to a littoral state's exclusive right to economic exploitation of resources on and under the sea-bed, for instanceoil drilling, in an area adjacent to itsterritorial waters and extending into theHigh Seas. The width of the continental shelf is commonly defined for purposes of international law as not exceeding 200nautical miles. Where the territories of two states lie closer opposite each other than double that distance, the division is made by themedian line.The concept of the continental shelf is closely connected to that of anexclusive economic zone, which refers to a littoral state's control overfishery and similar rights. Both concepts were developed in international law from the middle of the 20th century and were codified in theUnited Nations Convention on the Law of the Sea in 1982.

The dispute between Turkey and Greece is to what degree the Greek islands off the Turkish coast should be taken into account for determining the Greek and Turkish economic zones. Turkey argues that the notion of "continental shelf", by its very definition, implies that distances should be measured from the continental mainland, claiming that the sea-bed of the Aegean geographically forms anatural prolongation of theAnatolian land mass. This would mean for Turkey to be entitled to economic zones up to the median line of the Aegean (leaving out, of course, the territorial waters around the Greek islands in its eastern half, which would remain as Greek exclaves.) Greece, on the other hand, claims that all islands must be taken into account on an equal basis. This would mean that Greece would gain the economic rights to almost the whole of the Aegean.^[2]

In this matter, Greece has the UN Law of the Sea on its side, but the same Convention restricts the application of this rule^[7] to islands of a notable size, as opposed to small uninhabitableislets and rocks. The precise delimitation of the economic zones is the only one of all the Aegean issues where Greece has officially acknowledged that Turkey has legitimate interests that might require some international process of arbitration or compromise between the two sides.^[5] Turkey cites the resolution of certain International Court of Justice cases like Territorial and Maritime Dispute (Nicaragua v. Colombia),^[8]Maritime Delimitation in the Black Sea case,Canada–France Maritime Boundary Case where court had used equitable approach and limited the continental shelves of islands.^{[citation needed]}

Tensions over the continental shelf were particularly high during the mid-1970s and again the late 1980s, when it was believed that the Aegean Sea might hold richoil reserves. Turkey at that time conducted exploratoryoceanographic research missions in parts of the disputed area. These were perceived as a dangerous provocation by Greece, which led to a buildup of mutual military threats in 1976 and again in 1987.^[5]

Unlike the issues described so far, the question offlight information regions (FIR) does not affect the two states' sovereignty rights in the narrow sense. A FIR is a zone of responsibility assigned to a state within the framework of theInternational Civil Aviation Organization (ICAO). It relates to the responsibility for regulating civil aviation. A FIR may stretch beyond the national airspace of a country, i.e. over areas ofhigh seas, or in some cases even over the airspace of another country. It does not give the responsible state the right to prohibit flights by foreign aircraft; however, foreign aircraft are obliged to submit flight plans to the authorities administrating the FIR. Two separate disputes have arisen over flight control in the Aegean: the issue of a unilaterally proposed revision of the FIR demarcation, and the question of what rights and obligations arise from the FIR with respect to military as opposed to civil flights.^{[citation needed]}

By virtue of an agreement signed in 1952, the whole airspace over the Aegean, up to the boundary of the national airspace of Turkey, has been assigned to Athens FIR, administered by Greece. Shortly after theCyprus crisis of 1974, Turkey unilaterally attempted to change this arrangement, issuing a notice to airmen (NOTAM) stating that it would take over the administration of the eastern half of the Aegean airspace, including the national airspace of the Greek islands in that area. Greece responded with a declaration rejecting this move, and declaring the disputed zone unsafe for aviation due to the conflicting claims to authority. This led to some disruption in civil aviation in the area. Turkey later changed its stance, and since 1980 has returned to recognizing Athens FIR in its original demarcation.^[5] In practice, the FIR demarcation is currently no longer a disputed issue.

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As of 2009,^[update] the current controversy over the FIR relates to the question whether the Greek authorities have a right to oversee not only civil but also military flight activities in the international parts of the Aegean airspace. According to common international practice, military aircraft normally submit flight plans to FIR authorities when moving in international airspace, just like civil aircraft do. Turkey refuses to do so, citing the ICAO charter of 1948, which explicitly restricts the scope of its regulations to civil aircraft, arguing that therefore the practice of including military aircraft in the same system is optional. Greece, in contrast, argues that it is obligatory on the basis of later regulations of the ICAO, which it claims have given states the authority to issue more wide-reaching restrictions in the interest of civil aviation safety.

This disagreement has led to similar practical consequences as the issue of 6 versus 10 miles of national airspace, as Greece considers all Turkish military flights not registered with its FIR authorities as transgressions of international air traffic regulations, and routinely has its own air force jets intercepting the Turkish ones. In popular perception in Greece, the issue of Turkish flights in the international part of Athens FIR is often confused with that of the Turkish intrusions in the disputed outer 4-mile belt of Greek airspace.^{[citation needed]} However, in careful official usage, Greek authorities and media distinguish between "violations" (παραβιάσεις) of the national airspace, and "transgressions" (παραβάσεις) of traffic regulations, i.e. of the FIR.

One of the routine interception maneuvers led to a fatal accident on 23 May 2006. Two TurkishF-16s and one reconnaissanceF-4 were flying in the international airspace over the southern Aegean at 27,000 feet (8,200 m) without having submitted flight plans to the Greek FIR authorities. They were intercepted by two Greek F-16s off the coast of the Greek islandKarpathos. During the ensuing mock dog fight, a Turkish F-16 and a Greek F-16 collided midair and subsequently crashed. The pilot of the Turkish plane survived the crash, but the Greek pilot died. The incident also highlighted another aspect of the FIR issue, a dispute over conflicting claims to responsibility for maritimesearch and rescue operations. The Turkish pilot reportedly refused to be rescued by the Greek forces that had been dispatched to the area. After the incident, both governments expressed an interest to revive an earlier plan of establishing a direct hotline between the air force commands of both countries in order to prevent escalation of similar situations in the future.

On 2 September 2019,Turkey's PresidentRecep Tayyip Erdoğan appeared in a photograph with a map that depicted nearly half of the Aegean Sea and an area up to the eastern coast of Crete as belonging to Turkey. The map was displayed during an official ceremony at theNational Defense University of Turkey in Istanbul^[37] and shows an area labelled as "Turkey's Blue Homeland" stretching up to the median line of the Aegean,^[38] enclosing the Greek islands in that part of the sea without any indication of the Greek territorial waters around them. The Blue Homeland is anirredentist andexpansionist concept and doctrine,^[a] compared to the German concept ofLebensraum;^[48] it was created by the Chief of Staff of the Turkish Navy CommanderCihat Yaycı, and developed with Admiral Cem Gurdeniz in 2006.^{[49][50][51][40]} The Greek side expressed its regret, with the Greek Foreign MinisterNikos Dendias stating that Turkey's tactics are "communication campaigns that cannot change international legitimacy, merely establishing Turkey's image as a perpetrator".^[52]

On 13 November 2019, Turkey submitted to the United Nations a series of claims to Exclusive Economic Zones in the Eastern Mediterranean that are in conflict with Greek claims to the same areas – including a sea zone extending west of the southeastern Aegean island of Rhodes and south of Crete. The Turkish claims were made in an official letter by Turkey's Permanent Representative to the UNFeridun Sinirlioglu, which reflect Ankara's notion of a "Blue Homeland" (Mavi Vatan). Greece condemned these claims as legally unfounded, incorrect and arbitrary, and an outright violation of Greece's sovereignty.^[53]

Turkey holds the view, unlike most other states,^{[54][55][56][57][58][59]} that no islands can have a fullExclusive Economic Zone (EEZ)^[60][61] and should only be entitled to a 12 nautical mile reduced EEZ or no EEZ at all rather than the usual 200 miles that Turkey and every other country are entitled to. In this context, Turkey, for the first time on 1 December 2019, claimed that the Greek island ofKastellorizo shouldn't have any EEZ at all, because, from the equity-based^[62][63] Turkish viewpoint, it is a small island immediately across the Turkish mainland (which, according to Turkey, has thelongest coastline), and isn't supposed to generate a maritime jurisdiction area four thousand times larger than its own surface.^[64] Furthermore, according to Turkey's Foreign Ministry, an EEZ has to be coextensive with the continental shelf, based on the relative lengths of adjacent coastlines^[59] and described any opposing views supporting the right of islands to their EEZ as "maximalist and uncompromising Greek and Greek Cypriot claims".^[63][62][65] On 20 January 2020, the Turkish President Erdogan challenged even the rights of Crete, Greece's largest island and5th largest in the Mediterranean, stating that "They talk about a continental shelf around Crete. There is no continental shelf around the islands, there is no such thing, there, it is only sovereign waters."^[66]

Turkey's view, however, is a 'unique' interpretation^[67][59] not shared by any other country and not in accordance to the United Nations' Convention on the Law of the Sea (UNCLOS) treaty, which as of May 2022 has been signed by 168 parties (including Greece), but not Turkey.^[68] Turkey did not ratify the UNCLOS, and argues that it is not bound by its provisions that award islands maritime zones. The UNCLOS, and particularly Article 121 clearly states that the islands can have exclusive economic zones and continental shelf just like every other land territory.^[69] The Ambassadors of the United States and Russia to Athens,Geoffrey Pyatt and Andrey Maslov respectively, while commenting on Turkey's view, stated that all the islands have the same rights to EEZ and continental shelf as the mainlands do.^[70][71][72] The thenUS Assistant Secretary of State for European and Eurasian Affairs,Aaron Wess Mitchell, criticized the Turkish view on Cyprus's EEZ, stating that it "is a minority of one versus the rest of the world."^[73]

On 28 November 2019, President Erdoğan signed a Memorandum of Understanding (MoU) in Istanbul with the Prime Minister of theTripoli-basedGovernment of National Accord of Libya (GNA),Fayez al-Sarraj, to demarcate maritime zones in the Eastern Mediterranean on an area between Turkey and Libya, appearing to "write [the Greek island of] Crete off the map entirely" in the words ofForeign Policy's Keith Johnson.^[74]

This agreement was controversial^[75][76][77] and drew condemnation by Greece and the international community, including the rivalTobruk-based government led by theLibyan House of Representatives andKhalifa Haftar, theEuropean Union,United States,Russia,Egypt,Cyprus,Malta,France,Germany,Italy,Sweden,Serbia,Israel,Syria,Bahrain,Saudi Arabia, theUnited Arab Emirates and theArab League, as a violation of the International Law of the Sea and the article 8 of theSkhirat Agreement which prohibits the Libyan Prime Minister from solely clinching international deals without consent of all the cabinet members.^[b] The Libyan House of Representatives consequently started a bid to suspend the GNA from the Arab League, but did not succeed.^[106] The United States stated that it was "provocative" and a threat to the stability of the region.^[107][108] Acting foreign ministerIsrael Katz announced Israel's opposition to the maritime border accord between Ankara and Tripoli, and confirmed that the deal was "illegal" according to the Israeli official position, while at the same time noting that Israel does not want a conflict with Turkey.^[109]

On 18 October 2020, theGerman Federal Parliament (Bundestag)'s research service reviewed the Turkey-GNA maritime deal and found it to be illegal under international law, and detrimental to third parties.^[110]

In response to these developments, the GNA Ambassador to Greece Mohamed Younis Menfi was summoned to the Greek Ministry of Foreign Affairs in Athens, where he was given anultimatum of seven days, to disclose until 5 December the agreement his country signed with Turkey on maritime boundaries, or will be considered "persona non-grata" and be expelled from Greece.^[111] The authorities of the European Union also urged for the disclosure of the deal's details.^[90] Also, the Greek Prime MinisterKyriakos Mitsotakis met with the Turkish President on the sidelines of the2019 London summit to discuss about it.^[112] Greek Foreign Minister Dendias revealed in September 2019 that his GNA counterpart, foreign minister Mohamed Taher Siala had reassured the Greek side that Libya would never sign any illegal agreements with Turkey that would violate the Greek sovereign rights.^[113][114]On 6 December, the GNA Ambassador to Athens was expelled from Greece,^[115] prompting strong reactions in both the GNA and Turkey.^[116][77] Furthermore, the President of the Tobruk-based Libyan Parliament, Agila Saleh Issa Gwaider, who condemned and opposed the GNA-Turkey deal, was invited to Athens by the President of the Greek Parliament Konstantinos Tasoulas for talks.^[117]

Ankara asked for the agreement on maritime boundaries from the Government of National Accord (GNA) in theLibyan Civil War, in exchange for Turkey's long-time support against the rival Tobruk-based House of Representatives.^[118]

It is believed, according to multiple sources, that Turkey's President Recep Tayyip Erdogan is exploiting the weakness of the GNA headed by Fayez al-Sarraj to force it to sign "illegal" agreements which are a serious breach of international laws that disregards the lawful rights of other eastern Mediterranean countries; and that through these exploitations, Turkey is trying to assert its regional power and its control of the Mediterranean sea, at the expense of the rights of the other Mediterranean nations and undermining the peace-making efforts to resolve the Libyan Civil War and the curb of migrant influx to Europe.^{[119][120][121][122][123][124][125][126]}

On 4 December 2019, the Turkish Minister of Energy and Natural Resources, Fatih Dönmez, announced Turkey's intentions to start awarding licences to drills for natural gas in Greek waters which Ankara claimed through the Turkey-GNA deal, once it is approved by the two countries' parliaments.^[127] The same day, Turkish President Erdogan stated that he is "ready" to start negotiations with Athens for the delimitation of maritime borders between Turkey and Greece, under the condition that the negotiations are based on Turkey's peculiar perception which is stripping the Greek islands of their sovereign rights, and is violating the UNCLOS treaty.^[128]The intentions for drills in Greek waters, was confirmed by President Erdogan on a public broadcast of the Mavi Vatan map and the Turkey-GNA deal.^[129] On 5 December 2019, the Turkish Parliament ratified the contentious GNA-Turkey maritime borders deal, where it had a strong backing by four of Turkey's five major political parties - with the exception of the pro-Kurdish People's Democracy Party (HDP).^[130][131] The Libyan Parliament however blocked the ratification and rejected the deal unanimously, with the President of the Parliament,Aguila Saleh Issa, sending a letter to the United Nations declaring it as null and void.^{[132][133][134][135]} Even though the ratification by the Libyan Parliament failed, GNA deposited the maritime agreement to the United Nations on 27 December,^[136] with Turkey following on 2 March of the next year.^[137] On 14 July 2020, it is revealed that five countries sent a joint note verbale to the UN Secretariat calling for the agreement to not be registered and accepted, noting that, per UN procedures, its ratification by the Libyan Parliament is a prerequisite.^[104] On 1 October, the UN Secretary-General, Antonio Guterres, registered the Turkey-GNA deal on the delimitation of maritime jurisdiction areas in the Mediterranean. The agreement "has been registered with the Secretariat, in accordance with Article 102 of the Charter of the United Nations," said the certificate of registration.^[138][139] On 27 January 2021, a court of appeals inAl-Bayda ruled in favour of a lawsuit filed by the House of Representatives, declaring the Memorandum invalid.^{[140][141][142]}

According to multiple sources, there is a fear of destabilization in the East Mediterranean and NATO due to Turkey's assertive moves and that an armed conflict between Turkey and Greece draws closer.^{[143][144][145][146][147][148][149][150][151]} On 9 December, the vessels of theLibyan Navy which are under the control of the Libyan National Army, announced that they received mandate to sink any Turkish research vessels or drillships that may attempt to conduct researches south of Crete, as part of the Turkey-GNA deal.^[152] France also signaled its intention to send French frigates and ships to the south of Crete, in coordination with Athens, while Italy sent its frigate "Martinengo" to monitor, patrol and safeguard the sea around Cyprus, which has been the subject of claims by Turkey.^[153][154]

On 30 May 2020, theTurkish Petroleum Corporation (TPAO) applied to the Turkish Ministry of Energy for exploration permits on the Greek continental shelf, just 6 miles off Crete, Karpathos and Rhodes.^[155][156] TPAO's applications were published to the Turkey's Government Gazette, with a map showing the 24 blocks that Ankara has demarcated from Turkey's shores to the point where its claimed sea borders meet these of Libya, based on the Turkey-GNA maritime agreement. This prompted strong reactions both in Greece and abroad, with the Turkish Ambassador to Athens, Burak Özügergin, being summoned to the Greek Foreign Ministry, and the European Union's High Representative of Foreign Affairs, Josep Borrell warning Ankara that the good EU-Turkey relations "will depend critically on the respect of the sovereignty of Cyprus and Greece on the waters under dispute".^{[157][158][159]} Furthermore, the United States criticized Turkey, with the US Assistant Secretary of State for Energy Resources Francis R. Fannon stating, during a quadrilateral conference organized by both the American-Hellenic Chamber of Commerce and theAtlantic Council with the participation of USA, Greece, Israel and Cyprus, that such "provocative actions" must end and that the Turkey-GNA agreement "cannot as a legal matter affect the rights or obligations of third states" such as Greece.^{[160][161][162]}

On 2 January 2020, the leaders of Greece, Cyprus, and Israel signed an accord to build theEastMed pipeline. The planned pipeline will transport natural gas from theLevantine Basin to Greece and from there to Italy and the rest of Europe.^{[163][164][165]} Energy expert Brenda Schaffer interprets the EastMed pipeline (forecasted to be able to cater to 10% of Europe's gas needs, and decrease reliance on Russia) as a joint attempt to exclude Turkey from the "Club Med" gas club,^[74] and the decision to sign the pipeline accord was taken in response to the Turkish-GNA deal.^[166]

On 19 May 2023,Claudio Descalzi, the CEO of Italian energy companyEni, said that any agreement for the construction of the EastMed pipeline must includeTurkey; he added that "there are disputes between Turkey and Cyprus that are difficult to remedy, furthermore Turkey has made an agreement withLibya to define a very vast platform that covers almost the entire EastMed, therefore not only Turkey but also Libya will have a say." In response to these comments, George Papanastasiou, the Cypriot Minister of Energy, Commerce and Industry, stated that not all people agree with the opinions expressed by Descalzi, and that he respects his opinion.^[167] These remarks follow reports that Eni, Cyprus and Israel are working on a deal for constructing a natural gas pipeline in the Eastern Mediterranean, connecting both the Cypriot and Israeli offshore gas fields to a processing plant in Cyprus, where thegas will be liquefied for export by ship to Italy and the rest of Europe.^[168][169]

On 9 June 2020, and in response to Turkey's moves in the region, Greece and Italy signed through their Foreign MinistersNikos Dendias andLuigi Di Maio a "historic" agreement for the demarcation of the EEZ between the two countries. The agreement confirms the full rights of islands to their continental shelf and EEZ, in line with the UNCLOS. It uses the median line that was used for the 1977 Italy-Greece continental shelf demarcation agreement as the basis of the EEZ boundary.^[170][171] In the mutually agreed minor adjustments, part of the EEZ of the small Greek islands ofStrofades,Othoni, andMathraki was traded off for an equal area elsewhere (i.e. part of the EEZ of Italy'sCalabria).^{[172][173][174]} According to Dendias, this creates an extremely favorable legal precedent for Greece in its dispute with Turkey.^[174] The United States, theLibyan House of Representatives, and theLNA led by Halifa Haftar, welcomed the EEZ agreement between Greece and Italy, with the US calling it "exemplary" and "an example of how these things should be done [in the region]", while reiterating their opposition to the Turkey-GNA EEZ agreement.^[175] Following the agreement, the Libyan House of Representatives sent an official invitation to theHellenic Parliament for a similar EEZ agreement to be reached between Libya and Greece too,^[176] with talks beginning on 1 July.^[177] Dendias stated that Libyan-Greek talks are "not within the arbitrariness that so-called Sarraj-Turkey memorandum is constituting", but within the framework of UNCLOS and in continuation of the 2010 talks between the two countries.^[177] In this context, a committee of experts is formed by the President of the Libyan Parliament, Aguila Saleh.^[178] The LNA published a map with the proposed EEZ boundaries between Libya and Greece, in which Libya fully acknowledges the Greek islands' rights to their continental shelf and EEZ.^[179] Furthermore, on 18 June, a high-level delegation from Greece visited Egypt to negotiate and sign an agreement demarcating the Egyptian-Greek EEZ as well.^[180]

In July 2020, France andAustria have called for sanctions against Turkey, such as the termination of theTurkey's EU accession talks. In the same context the EU'sForeign Affairs Council convened and agreed for a framework of sanctions to be prepared for use in the event Turkey attempts any violations of Greece's sovereign rights. The Greek FM Dendias expressed his country's readiness to activate the Mutual Defence Clause (Article 42) of the EU's Lisbon Treaty for military assistance.^{[181][182][183]}

On 21 July, Turkey announced plans for a seismic survey south and east of the Greek island of Kastellorizo with the research vessel "Oruç Reis", and for this purpose it issued a Navtex covering parts of the Greek, Egyptian and Cypriot waters,^[184] prompting strong reactions both in Greece^[185] and abroad. The Greek embassy in Ankara sent a complaint to the Turkish Foreign Ministry, Egypt considers the move as an encroachment of its waters,^[186] and Germany's Foreign MinisterHeiko Maas warned Turkey with consequences.^{[187][188][189][190]} Turkey dispatched its naval forces to the region around Kastellorizo, and Turkish armed jets conducted low overflights and dogfights with their Greek counterparts above the island, causing the tourists to evacuate it,^[191] and the Greek Armed Forces to be placed on high alert.^[192] The Turkish Ambassador to Berlin, Ali Kemal Aydın, was summoned to the German Foreign Ministry^[193] and theGerman ChancellorAngela Merkel held phone calls with the Greek Prime MinisterKyriakos Mitsotakis and the Turkish President Tayip Erdogan in a bid to de-escalate the situation.^[194][195] According to the German tabloid newspaperBild, it was Merkel's last-minute intervention that prevented a crisis between Greece and Turkey.^[196] This was later confirmed by the German Defence Minister,Annegret Kramp-Karrenbauer.^[197] Along with Germany, France, Spain and the United States also backed Greece, with theFrench PresidentEmmanuel Macron calling for sanctions against Turkey for the violation of Greece's sovereignty, the US envoy to Athens acknowledging Kastellorizo's "exactly the same" rights to EEZ and Continental Shelf as mainlands, and the State Department urging Turkey to halt its plans for surveys in the area around the island.^{[198][199][200][201][202]} A few days later, Turkey announced the suspension of its oil and gas exploration around Kastellorizo.^[203]

Several days later, on 6 August, the foreign ministers of Egypt and Greece,Sameh Shoukry and Nikos Dendias respectively, signed a maritime agreement partially demarcating the EEZs between the two countries, in line with the UNCLOS which recognizes the right of the islands to their continental shelf and EEZ.^{[204][205][206]} According to the Greek side, the Egyptian-Greek agreement cancels in practice the Turkish-GNA memorandum.^[207] Turkey opposed the agreement and considers it "null and void", claiming that "there is no mutual sea border between Egypt and Greece". Similarly, the Tripoli-based GNA government led by Al-Sarraj condemned it as a "violation of Libya's maritime rights".^[208] On the other hand, the Tobruk-based LNA government led by Haftar,^[209] Saudi Arabia and the United States, supported and welcomed it, with the LNA stating that Greece "should solidify a EEZ with the only democratically elected legislative body in Libya, the House of Representatives" and the US State Department stating that it encourages the peaceful settlement of disputes.^{[210][211][212][213]} Also,Manfred Weber, head of the European People's Party, the largest party in theEuropean Parliament, welcomed the Egypt-Greece agreement as a positive development that "strengthens stability in the East Mediterranean," and urged for the European Union to "stand firmly with Greece" against what he called as Turkish attempts that "undermine international law in the region".^[214] In response to this, Turkey announced the next day that it resumed its seismic surveys south of Kastellorizo.^[215][216] Τhe US, the EU, France, Germany, Austria, Italy, North Macedonia, Egypt, Cyprus, Israel, the United Arab Emirates, Spain, Portugal, Malta, Sweden andArmenia expressed their opposition to Turkey's renewed explorations in the East Mediterranean,^{[217][218][219][220][221][222][223][224][225][226][227][101][228]} whileAzerbaijan counteracted to Armenia's position by lending its support for Turkey's moves.^[229][230] On 14 August 2020, Greece's and Turkey's ships collided and suffered minor damages^[231] and France intervened by sending its naval forces to the East Mediterranean, to Greece's aid,^{[232][233][234]} followed by the United Arab Emirates whose Fighter Jets are stationed at theSouda Bay Naval Base, in Crete.^[235][236] Also, the United States beefed up their military presence in the East Med by assigning theUSS Hershel "Woody" Williams to the Souda Bay as its new permanent home,^[237][238] and talks on moving US assets from theIncirlik Air Base in Turkey, to Souda Bay opened.^[239] Josep Borrell announced that the European Union is preparing a list of sanctions against Turkey, including tough economic measures,^[240] and the former Turkish Prime MinisterAhmet Davutoglu criticized openly his own country's "power projection" in the East Mediterranean, which, according to him, risks causing a military conflict.^[241] On 18 August, theEgyptian Parliament ratified the Greece - Egypt EEZ Agreement^[242] and, 9 days later, the Greek Parliament followed suit,^[243] before it would be registered at the United Nations on 24 December 2020.^[244] Greece announced that reaching EEZ agreements with Albania and Cyprus are among its next priorities.^[245][246] On 17 September, theEuropean Parliament condemned Turkey for its violations of the Greek and Cypriot EEZs and called on the European Council to prepare further sanctions.^[247]

Due to Turkey's diplomatic isolation,^{[237][248][249][225][250]} and just a week ahead of the EU Summit where sanctions against theEU-candidate country for its drilling activities were to be evaluated, Oruç Reis withdrew from Kastellorizo and the Turkish surveys on Greek continental shelf were halted. Turkey agreed to resort to diplomatic means for resolving its maritime disputes with Greece.^{[251][252][253]} Turkey's economy is dependent on foreign markets and especially the European Union, for exports, imports, short-term finance and technology, and thus, the EU's tough economic sanctions could have a "fatal" impact on the Turkish economy and the Turkish President Erdogan's political survival.^[254] The prospect of EU sanctions also have contributed to the Turkish Lira's depreciation to record-low levels, worsening its economy.^{[255][256][257][258]} The United States, which criticized Turkey's assertive policies in the region, welcomed Ankara's decision to adopt a more diplomatic stance over its maritime dispute with Greece, with the head of the American foreign policy,Secretary of StateMichael R. Pompeo stating that "the way conflict is resolved is not through shows of force, it's not through demonstrations of power, it's through dialogue. It's through international systems, agreement, conversations, dialogue. That's how these maritime disputes ought to be resolved. We've watched the Greeks move in that direction trying to achieve that. We hope the Turkish Government will see it the same way". Additionally, Pompeo sided with Greece, by asking for a solution that is "reflective of the fundamental rights of the citizens of Greece".^{[259][260][250]}

On 8 October 2020, Turkey and Greece agreed, under Germany's mediation and with the United States' full consultation, to resume exploratory talks for resolving their maritime disputes. However, a few days later, on 11 October, Turkey withdrew from the talks and resumed itsgunboat diplomacy by releasing a NAVTEX announcing that it will be conducting surveys on the waters just 6.5 nautical miles off Kastellorizo^[261][262] and redeployed its research vessel Oruç Reis, escorted by Turkish frigates, for this purpose.^[263] These Turkish moves drew the International community's condemnation, with Berlin decrying them as a "serious blow" to efforts at easing tensions in the East Mediterranean and accusing Ankara for "interplay between detente and provocation",^{[101][264][265]} the German Foreign MinisterHeiko Maas cancelling his planned official visit to Ankara,^[266] and along with France, warning Turkey with consequences,^[267] Greece's Foreign MinisterNikos Dendias declaring that "the Turkish leadership has shown it is not a credible interlocutor. Its calls for dialogue are only a pretext. The international community must judge [Ankara] on the basis of actions, not words. We must all face reality before it is too late",^[268] the United States "deploring" Ankara for its moves, which the State Department described as "calculated provocations",^[269][270] Austria's ChancellorSebastian Kurz condemning Oruc Reis' redeployment and warning Turkey of sanctions,^[271][272] Egypt's Foreign MinisterSameh Shoukry rejecting Turkey's gunboat diplomacy and policy of territorial expansion in the region,^[273] Sweden's Foreign MinisterAnn Linde warning that the Oruç Reis' redeployment is leading to new tensions instead of contributing to de-escalation,^[101] Israel expressing its concerns over Turkey's destabilizing role in the East Med,^[274] and Russia backing Greece's right to expand its territorial waters to 12 nautical miles and reaffirming that the UNCLOS is a "cornerstone" of the international law and applies to the Mediterranean Sea.^[275]Manfred Weber of the EPP reiterated his call for EU sanctions against Turkey, stating that these initial de-escalation moves by Erdogan were purposeful only, with the aim of avoiding sanctions against his country at the recent European Council.^[276] Turkey however rebuffed international criticism of its research vessel's redeployment, insisting that the Oruç Reis is operating in what it claims as "Turkish waters".^[101]

On 17 October, Turkey passed a law expanding itssearch and rescue (SAR) area to cover all the new territories it claims in the Aegean and Mediterranean seas as part of its Blue Homeland theory.^{[277][278][279]} Greece condemned this extension of Turkish SAR as illegal under international law which does not permit any deliberate expansions of SAR areas without prior agreements with the relevant neighboring states, and protested strongly due to this expansion overlapping with Greece's Athens SAR and the sovereign rights of Greek islands and their surrounding waters. The Greek Ministry of Foreign Affairs filed a complaint against it at theInternational Civil Aviation Organization (ICAO) and theInternational Maritime Organization (IMO).^[280][281] Turkey described the Greek protests as "groundless", insisting that the expansion was done "to ensure the safety of the activities" within the Greek continental shelf which Ankara claims as "Turkish".^[282] ICAO's Secretary GeneralFang Liu, however, responded by rejecting Turkey's unilateral expansion of SAR and reaffirming the Greek position on the matter. According to Liu, no changes may be done to the SAR boundaries between the two countries without Greece's prior consent.^[283][284]

On 20 October, Greece and Albania agreed to resume negotiations for the demarcation of their maritime boundaries and that, in the event of no resolution, the two parties may jointly submit the case to theInternational Court of Justice inThe Hague.^{[285][286][287]} The two countries had already reached an agreement on the demarcation of their maritime boundaries in 2009. Although ratified by the Greek side, the Albanian one took it to the Albanian Supreme Court where it was deemed unconstitutional. According to Cihat Yaycı, a Turkish general and author of the Turkey's "Blue Homeland" theory, it was due to Ankara's pressure on Tirana that the agreement's ratification failed. For Turkey, an agreement between Albania and Greece based on the UNCLOS, would have had set a negative legal precedent against Turkey's positions in its maritime disputes with Greece.^{[288][289][290]} According to US diplomatic cables leaked in 2011, however, the Greek government had blackmailed Albania to accept an unfavourable deal using the veto power that Athens has over EU enlargement.^[291]

On 18 November, Greece and the United Arab Emirates formed amilitary alliance by signing amutual defense pact, which calls for each to help the other in case of an attack. The pact which is regarded as historic, marking the first of its kind in Greece's modern history, aims at countering Turkey's policies in the region.^{[292][293][294][295]}

Turkey was criticized at a NATO meeting on 3 December by the then US Secretary of State Mike Pompeo, for what he regarded as undermining NATO's security and cohesion and destabilizing the eastern Mediterranean by stoking tensions with fellow ally Greece, whilst according to Reuters, Turkish sources with knowledge of the meeting saw Pompeo's approach as "unjust" as Turkey was "open to talks with Greece".^[296][297] On 5 December, Turkey's Ministry of Foreign Affairs tweeted that "No sanctions will ever make Turkey compromise its sovereign rights, be it in Meis/Kastellorizo or 10 nm airspace."^{[298][299][300]} On 9 December, theUS House of Representatives adopted the National Defence Authorization Act (NDAA), a defense legislation which includes sanctionary measures against Turkey because of several international disagreements between Washington and Ankara, including the purchase of the Russian defence system S-400 and the Turkish activities in the Eastern Mediterranean region.^[301] Three days after its approval by theUS Congress, theDonald Trump administration imposed the sanctions as part of theCAATSA.^[302] According to SenatorRobert Menendez, a member of theUnited States Senate Committee on Foreign Relations and rapporteur of the NDAA amendment for US sanctions, Turkey's behavior in the East Med was one of the reasons contributing to the decision.^[303][304] The European Union's 27 leaders, also decided in the 10 December summit to impose sanctions on Turkey for its activities against Greece and Cyprus in the East Med. The EU sanctions include travel bans into the EU territories and asset freezes on Turkish companies and individuals.^[305][306]

On 18 September 2021, new diplomatic tensions sparked after an incident between Greece and Turkey where the latter's frigates prevented France's research vessel Nautical Geo from conducting surveys on Greece's behalf at the Greek EEZ, just 6 miles off the Greek island of Crete, whose waters Turkey claims as Turkish, citing its contentious maritime deal with the former Government of National Accord of Libya.^[307] The tensions come just a day after a high-level EUMed 9 Summit at Athens, where the heads of governments from 9 Mediterranean countries, including Croatia, Cyprus, France, Greece, Italy, Malta, Portugal, Slovenia and Spain, as well as the head of EU's Commission,Ursula von der Leyen, released a joint statement regarding the security and stability in the Mediterranean Sea, urging Turkey to "abstain, in a consistent and permanent manner, from provocations or unilateral actions in breach of international law".^{[308][309][310]} Turkey's Foreign Ministry rejected the summit's declaration, calling it "biased".^[311]

On 19 September, the main opposition party in Turkey, theRepublican People's Party (CHP), opposed the Mavi Vatan (Blue Homeland) doctrine as aggressive and expansionist.^{[312][313][314][315]}

On 28 September 2021, Greece andFrance signed theFranco-Greek defense agreement whereby either country is obliged to defend the other in the case of attack by a third party. France will supply Greece with navy frigates worth around €3 billion and is committed to help defend Greece if Turkey attacks.^[316] The pact is considered to be a landmark and the first of its kind ever signed between NATO allies, and is believed to be the first step in Europe's strategic autonomy and the creation of aEuropean army.^[317][318] The deal was welcomed positively by other NATO allies such as the United States^[319] Germany,^[320] and theEU's Commission,^[321] however it is opposed by Turkey as "harmful".^[322] According to experts, the deal aims to become the basis for the creation of a European defense structure with its own autonomous dynamics and priorities, and part of Greece's efforts in deterring Turkey'sneo-Ottoman expansionist policies in the region.^{[323][324][325][326][327][328][329]}

On 14 October, Greece and the United States expanded and indefinitely extended their defense pact amid tensions with Turkey. The agreement, known as theUS-Greece Mutual Defense Cooperation Agreement, promotes a strategic partnership between the two countries and grants the American forces a broader use of Greek bases, including a military base near theGreece-Turkey border. According to theUS Secretary of StateAntony Blinken, it aims at advancing "security and stability in the Eastern Mediterranean and beyond".^{[330][331][332]} Furthermore, in his letter accompanying the deal, Blinken vowed "to mutually safeguard and protect the sovereignty and territorial integrity of both countries against actions threatening peace, including armed attacks".^[333][334]

On 15 December 2021, Turkey's Foreign MinisterMevlüt Çavuşoğlu hinged Greece's sovereignty over the Aegean islands to their demilitarized status, claiming for the first time that Greece loses its sovereign rights even over the major Greek islands (such as Chios, Lesvos, and Rhodes),^[335] from the moment it has militarized them. According to him, this claim of sovereignty over islands being dependent to their demilitarization, was reiterated in Turkey's October 2021 letter to the United Nations as well.^{[336][337][338][339]} The international community however rejected Çavuşoğlu's positions. The Israeli ambassador to Athens,Yossi Amrani, when commenting about Çavuşoğlu's statements, pointed to the joint Israel, Cyprus and Greece declaration at the tripartite Jerusalem Summit earlier this month, which stressed the need for all countries to respect the sovereign rights of their neighbors in the region.^[340] Besides Israel and Cyprus, also the United States,^[341][342] the United Kingdom,^[343][344] France,^[345][346] Germany,^[347][348] Ireland,^[349] the European Union,^[350][351]Egypt^[352][353] and China^[354] lend their support to Greece, with the State Department stating that "the sovereignty and territorial integrity of all countries must be respected and protected. The sovereignty of Greece οn these islands is not in question," and the European Union expressing its disapproval, stating that "the sovereignty of Greece in these islands is indisputable" and that "the international agreements must be respected." The US ambassador to Athens Geoffrey Pyatt also affirmed his country's solidarity with Greece against the Turkish claims.^[355] A few days later, however, the Turkish President Erdogan, reiterated Çavuşoğlu's statements, insisting that their militarization is a "violation of [international] treaties" and that "the issue of the islands is always controversial".^[356] Greece's Foreign Minister Nikos Dendias expressed his regret for Erdogan's remarks, stating that they go against the spirit of the United Nations's Universal Declaration of Human Rights (UDHR) and raises questions about Turkey's membership in the North Atlantic Alliance (NATO).^[357] Turkey's retired ambassadors,Yalım Eralp [tr] andSelim Kuneralp, questioned their country's foreign policy regarding the Greek islands, noting that it is harmful for its own interests. While commenting on the Turkish government's attempts to challenge their sovereignty, Eralp stated that "There are many claims of sovereignty that the islands were given on condition [of demilitarization]. There is no such thing. The islands located beyond three miles were given to Greece and Turkey has accepted it for many years. Putting this into question now – in diplomacy – makes Turkey an aggressive state", adding that "there are over 2,400 islands and islets in the Mediterranean. A treaty to count all these islands is out of the question. We have not seen it [happening] anywhere. [The Treaty of] Lausanne gave the islands beyond three miles to Greece, whether we like it or not."^{[358][359][360][361]}

On 9 July 2022, officials from Turkey'sAKP-led ruling coalition, thePeople's Alliance, appeared for the first time in photographs with a revisionist map claiming Greece's largest island,Crete, as belonging to Turkey. Besides Crete, the entire eastern half of the Aegean Sea, its islands and their waters, which were initially claimed as part of the "Blue Homeland" doctrine, are also shown as Turkish. This prompted strong reactions and condemnation both in Greece and abroad, with Athens regarding the unprecedented move as an aggressive act, and the Greek Prime Minister asking publicly the Turkish President to clarify his position on the new map, something he avoided doing.^{[362][363][364][365][366]} The United States and Germany also rebuked the map's claims as unacceptable.^{[367][368][369]} Following these developments, the head of the US Senate Committee on Foreign Relations, Senator Robert Menendez, announced congressional amendments conditioning future US arm sales ofF-16 to Turkey on its respect of Greek sovereignty.^[370][371] These amendments which require that the US administration shows theUS Congress that Turkey has "not violated the sovereignty of Greece" in the past 120 days prior to the sale, and that concrete steps have been taken "to ensure no such F-16s are used by Turkey for repeated unauthorized territorial overflights of Greece", passed on 14 July.^[372][373]

On August 23, Turkey's Defense Ministry claimed that Greek Air Force fighter jets placed radar locks on Turkish F-16s escorting US B-52 bombers as part of the NATO mission. Following the incident, Turkey summoned the Greek military attaché and filed a complaint with NATO.^[374] A few days later, it also claimed that the radar of a Greek S-300 missile system based on the island of Crete has been used to locked on to the Turkish F-16s.^[375] These allegations were denied by Greece, while a Western military official noted that Turkey has yet to provide any evidence to support them.^[34][35] According to experts, it is believed that Turkey usesfake news regarding the use of S-300 by Greece to create analogies between Turkey's S-400 and Greece's S-300 in a bid to convince the US administration to lift theCountering America's Adversaries Through Sanctions Act (CAATSA) sanctions which wereimposed on Turkey for acquiring them from Russia.^[376] However the United States refuted Turkey's attempts to create any analogies between its S-400 and Greece's S-300.^[377] In the past, Turkey has again unsuccessfully attempted to justify the use of S-400 and thus lift the CAATSA sanctions on Ankara, by pointing again to Greece's S-300.^[378]

By 3 September 2022, Turkey's President Recep Tayyip Erdoğan threatened Greece with a Turkish military invasion of the Greek islands which, according to him, are "occupied".^[c] Greece responded by reiterating its right to defend its islands against what it described as an "expansionist" Turkish stance,^[388] and pointed toTurkey's Aegean coast just opposite the Greek islands, noting that Turkey maintains there itslanding fleet, the largest in Europe, along with afull formation of its army.^[389][390] Greece furthermore announced that it is informing the United Nations and NATO about the leader's remarks. The European Union and its presiding country, theCzech Republic condemned Erdoğan's threats as "unacceptable",^[391] whileFrance's Foreign MinisterCatherine Colonna responded by recalling themutual assistance clause signed last year that unites Paris and Athens.^[392][393] According to the international media, the Turkish leader's remarks constituted an escalation of his rhetoric as he was preparing for the2023 elections in his country, which are seen as crucial for his nearly 20-year rule; increasing the political rhetoric against a neighboring country would rally hisnationalist base amidTurkey's ongoing economic troubles.^[389][394] According to Greek analysts, these threats of invasion made Greece's position appear more credible to the international community as the need to maintain a military presence on its islands for deterrence against Turkey is now fully justifiable.^[34]

On 11 December, Erdogan also stated that the Turkish-manufactured Tayfun missiles "will hit Athens", Greece's capital city, if the Greek islands continue to be armed up.^{[395][396][397]}

On 10 January 2023, the Court of Appeals of Tripoli suspended an energy exploration deal signed a few months earlier, on 3 October 2022, between Turkey and Libya's Government of National Unity (GNU) which is based at Tripoli. The agreement had included scope for oil and gas exploitation in waters that Ankara and Tripoli have claimed as their own through the 2019 Turkey–GNA maritime agreement, which partially overlaps with waters claimed by Egypt and Greece as part of their 2020 EEZ agreement.^[398]

In February 2023, south-central Turkey was hit bydevastating earthquakes, to which Greeceresponded immediately by sending quake-relief aid.^[399] The newspaperSüddeutsche Zeitung noted that the Greek aid came despite severe diplomatic tensions in recent months, and Erdoğan's repeated threats to militarily invade Greece's islands.^[400] According to Deutsche Welle, these developments marked the revival of theGreek–Turkish earthquake diplomacy of 1999 between the two countries, once again.^[401] This improvement in the bilateral relations, resulted in the cessation of Turkey's practice of military overflights above Greece's territories and the violations of its national airspace, ever since.^[402]

In December 2023, Turkish President Erdoğan visited Athens for talks with Greek PM Mitsotakis. This was the first visit in 6 years and the talks were held in a positive atmosphere and considered a success after recent bad relations. No major disputes were resolved, however, the two leaders signed a non-binding declaration of friendship, and numerous bilateral agreements; including managing migration flows, and committed to continuing talks in Ankara in the spring of 2024.^[403]

Tensions were raised again in July 2024, when five Turkish warships put pressure on research vessels nearKarpathos for the laying of undersea power cables linking Greece with Cyprus and Israel. The tension was diffused when the research vessels withdrew.^[404] In March 2025, the Greek government suspended the plannedGreat Sea Interconnector mainly due to Turkey's objections.^[405] This follows the suspension of theEastMed Gas pipeline, which was also meant to connect Greece and Cyprus with Israel and Egypt through the disputed waters.

There have been a number of disputes related to the territories of the Greek islands themselves. These have related to the demilitarized status of some of the main islands in the area; to Turkish concerns over alleged endeavours by Greece to artificially expand settlements to previously uninhabited islets; and to the existence of alleged "grey zones", an undetermined number of small islands of undetermined sovereignty.^{[citation needed]}

The question of thedemilitarized status of some major Greek islands is complicated by a number of facts. Several of the Greek islands in the eastern Aegean as well as the Turkish straits region were placed under various regimes of demilitarization in different international treaties. The regimes developed over time, resulting in difficulties of treaty-interpretation.^{[citation needed]} However, the military status of the islands in question did not constitute a serious problem in the bilateral relations until theCyprus crisis of 1974, after which both Greece and Turkey re-interpreted the stipulations of the treaties. Greece, claiming an inalienable right to defend itself against Turkish aggression, reinforced its military and National Guard forces in the region. Furthermore, Greece maintains the position that it has the right to militarize its islands in the same context as the rest of Europe, where the appliance of demilitarization statute on islands and territories ceased with the creation of theNorth Atlantic Treaty Organization and theWarsaw Pact; i.e. the cessation of demilitarization of Italy's Panteleria, Lampedusa, Lampione and Linosa islands, and West Germany from the NATO side, and the cessation of demilitarization of Bulgaria, Romania, East Germany, and Hungary from the Warsaw Pact's side, and the cessation of demilitarization of Finland.^[406] Turkey, on the other hand, denounces this as an aggressive act by Greece and as a breach of international treaties.^[4] From a legal perspective, three groups of islands may be distinguished: (a) the islands right off the TurkishDardanelles straits, i.e.Lemnos andSamothrace; (b) theDodecanese islands in the southeast Aegean; and (c) the remaining northeast Aegean islands (Lesbos,Chios,Samos, andIkaria).

These islands were placed under a demilitarization statute by theTreaty of Lausanne in 1923, to counterbalance the simultaneous demilitarization of the Turkish straits area (theDardanelles andBosphorus),Imbros andTenedos. The demilitarization on the Turkish side was later abolished through theMontreux Convention Regarding the Regime of the Turkish Straits in 1936. Greece holds that, by superseding the relevant sections of the earlier treaty, the convention simultaneously lifted also the Greek obligations with respect to these islands. Against this, Turkey argues that the Montreux treaty did not mention the islands and has not changed their status.^[4] Greece, on the other hand, cites Turkish official declarations, by the then Turkish Minister for Foreign Affairs, Rustu Aras, to that effect made in 1936,^[407] assuring the Greek side that Turkey would consider the Greek obligations lifted.^[5]

These islands were placed under a demilitarization statute after the Second World War by theTreaty of peace with Italy (1947), whenItaly ceded them to Greece. Italy had previously not been under any obligation towards Turkey in this respect. Turkey, in turn, was not a party to the 1947 treaty, having been neutral during WWII. Greece therefore holds that the obligations it incurred towards Italy and the other parties in 1947 areres inter alios acta for Turkey in the sense of Article 34 of theVienna Convention on the Law of Treaties, which states thata treaty does not create obligations or rights for a third country, and that Turkey thus cannot base any claims on them. Turkey argues that the demilitarization agreement constitutes astatus treaty (anobjective régime), where according to general rules of treaty law such an exclusion does not hold.

The remaining islands (Lesbos,Chios,Samos, andIkaria) were placed under a partial demilitarization statute by theTreaty of Lausanne in 1923. It prohibited the establishment of naval bases and fortifications, but allowed Greece to maintain a limited military contingent recruited from the local population, as well as police forces. With respect to these islands, Greece has not claimed that the treaty obligations have been formally superseded. However, in recent years it has argued that it is entitled to discount them, invoking Article 51 of theCharter of the United Nations. It argues that after the Turkish occupation of northernCyprus and the Turkish threat of war over the 12 miles issue, re-armament is an act of legitimate self-defence.^[5]

The first time a dispute between the two countries in the Aegean touched on questions of actual sovereignty over territories was in early 1996 at the tiny barren islets ofImia (known as Kardak in Turkey), situated between theDodecanese island chain and the Turkish mainland.^[408] The conflict, triggered by the stranding of a Turkish merchant ship on the islets, was originally caused by factual inconsistencies between maps of the area, some of which assigned these islets to Greece, others to Turkey. The media of the two countries took up the issue and gave it a nationalistic turn, before the two governments even had the time to come to a full technical understanding of the true legal and geographical situation. Both governments finally adopted an intransigent stance, publicly asserting their own claims of sovereignty over the islets. The result was military escalation, which was perceived abroad as quite out of proportion with the size and significance of the rocks in question. The two countries were at the brink of war for a few days, until the crisis was defused with the help of foreign mediation.^[409]

During the crisis and in the months following it, both governments elaborated legal arguments to support their claims to sovereignty. The arguments exchanged concerned the interpretation of theTreaty of Lausanne of 1923, which forms the principal basis for the legal status of territories in most of the region, as well as certain later diplomatic dealings between Turkey, Greece and Italy.

In the wake of the Imia crisis, the Turkish government widened its argumentation to include not only Imia but also a possibly large number of other islands and small formations across the Aegean. Since then, Turkish authorities have spoken of "grey zones" of undetermined sovereignty. According to the Turkish argument, these islets, while not explicitly retained under Turkish sovereignty in 1923, were also not explicitly ceded to any other country, and their sovereignty has therefore remained objectively undecided.

The Turkish government has avoided stating exactly which islets it wishes to include in this category. On various occasions, Turkish government sources have indicated that islands such asPserimos,Agathonisi,Fournoi andGavdos^[410] (situated south ofCrete) might be included. Most of them, unlike Imia, had undeniably been in factual Greek possession, which had never previously been challenged by Turkey, and all but the final two listed below have Greek residents and infrastructure. Furthermore, the islands are covered by previous treaties such as the Treaty of Lausanne, which defines Turkish sovereignty as limited to within 3 miles of the Anatolian mainland in the majority of cases.^[410] In a 2004 publication by Turkish authors close to the Turkish military leadership^[411] the following (among other, even smaller ones) were listed as potentially "grey" areas:

• Oinousses (betweenChios and the Turkish coast),
• Antipsara (west of the islands of Psara and Khios),
• Fournoi,
• Arkoi,
• Agathonisi (Gaidaros),
• Pharmakonisi,
• Kalolimnos (near Imia),
• Pserimos,
• Gyali (betweenKos andNisyros),
• Syrna (SE ofAstypalaia)
• Kandheliousa (south ofKos),
• Kalogeroi (islets) (small rocks 41 km northeast ofAndros)

While Turkey has not attempted to challenge Greek sovereignty on the ground, its claims about "grey area" islands add to the number of minor military incidents, already numerous due to the 10-mile airspace and the FIR issues. Greek authorities routinely report that the Turkish Air Force ignores their national airspace. According to Greek press reports, the number of airspace violations rose sharply in 2006, as did the number of unauthorized Turkish military flights directly over Greek islands themselves.^[412] Renewed reports of systematic Turkish military flights directly over Greek islands like Pharmakonisi and Agathonisi were made in late 2008 and early 2009.^[413]

During the late 2010s, tensions rose again as Turkish fighter aircraft increased the number of direct armed overflights above inhabited Greek islands. While most overflights continue to occur above small islands that Turkey considers "grey areas", such as Agathonisi or Oinousses, some incidents have also repeatedly been reported involving major and undisputed islands such asRhodes,Lesbos,Chios orLeros.^{[414][415][416][417]} Flying over the territory of a country is considered a serious violation of its sovereignty^[418] and one of the most provocative acts by Turkey, directly challenging Greek territorial sovereignty.^[419]

In 2020, Turkish fighter aircraft also begun overflights above theGreek mainland, onEvros.^[420][421]

A regional Foreign Minister conference held on 11 May 2020 with the participation of Cyprus, Egypt, France, Greece and the United Arab Emirates, concluded with a joint declaration condemning Turkey for its practice of conducting armed overflights above the inhabited Greek islands.^[422][423]

In 2022, Turkish bomber aircraft approached the major Greek city ofAlexandroupolis on Evros, within 2.5 miles. The jets reportedly flew near the US base located in the city's port.^[424] This move is considered to be unprecedented, prompting protests from both the Greek authorities and the European Union, as well as USA's disapproval, with the Head of Turkey's Permanent Representation to the European Union Mehmet Bozay being summoned at Brussels by the Secretary General of the European Union External Action Service, Stefano Sannino.^{[425][426][427]}

In September 2009, aTurkish military radar issued a warning to aLatvian helicopter patrolling in the easternAegean—part of the EU'sFrontex programme to combat illegal immigration—to leave the area. TheTurkish General Staff reported that the Latvian Frontex aircraft had violated Turkish airspace west ofDidim.^[428]According to aHellenic Air Force announcement, the incident occurred as the Frontex helicopter—identified as an Italian-madeAgusta A109—was patrolling in Greek air space near the small isle ofFarmakonisi, which lies on a favorite route used bymigrant smugglers ferrying mostly illegal migrants into Greece and the EU from the opposite Turkish coastline.^[429] Frontex officials stated that they simply ignored the Turkish warnings as they did not recognise their being in Turkish airspace and continued their duties.

Another incident took place in October 2009 in the aerial area above the eastern Aegean sea, off the island ofLesbos.^[430] On 20 November 2009, the Turkish General Staff issued a press note alleging that anEstonian Border Guard aircraftLetL-410 UVP taking off fromKos on a Frontex mission had violated Turkish airspace west ofSöke.^[428]

The decades since the 1970s have seen a repeated heightening and abating of political and military tensions over the Aegean. Thus, thecrisis of 1987 was followed by a series of negotiations and agreements inDavos andBrussels in 1988. Again, after the Imia crisis of 1996, there came an agreement over peaceful neighbourly relations reached at a meeting inMadrid in 1997. The period since about 1999 has been marked by a steady improvement of bilateral relations.

For years, the Aegean dispute has been a matter not only about conflicting claims of substance. Rather, proposed strategies of how to resolve the substantial differences have themselves constituted a matter of heated dispute. Whereas Turkey has traditionally preferred to regard the whole set of topics as apolitical issue, requiring bilateral political negotiation,^[1] Greece views them asseparate and purelylegal issues,^[431] requiring only the application of existing principles of international law. Turkey has advocated direct negotiation, with a view to establishing what it would regard as an equitable compromise. Greece refuses to accept any process that would put it under pressure to engage in a give-and-take over what it perceives as inalienable and unnegotiable sovereign rights. Up to the late 1990s, the only avenue of conflict resolution that Greece deemed acceptable was to submit the issues separately to theInternational Court of Justice inThe Hague.

The resulting stalemate between both sides over process was partially changed after 1999, when the European summit of Helsinki opened up a path towardsTurkey's accession to the EU. In the summit agreement, Turkey accepted an obligation to solve its bilateral disputes with Greece before actual accession talks would start. This was perceived as giving Greece a new tactical advantage over Turkey in determining which paths of conflict resolution to choose. During the following years, both countries held regular bilateral talks on the level of technical specialists, trying to determine possible future procedures. According to press reports,^[432] both sides seemed close to an agreement about how to submit the dispute to the court at The Hague, a step which would have fulfilled many of the old demands of Greece. However, a newly elected Greek government underKostas Karamanlis, soon after it took office in March 2004, opted out of this plan, because Ankara was insisting that all the issues, including Imia and the "grey zones", belonged to a single negotiating item. Athens saw them as separate. However,^[432] Greek policy remained at the forefront in advocating closer links between Ankara and the EU. This resulted in the European Union finally opening accession talks with Turkey without its previous demands having been fulfilled.

According to some commentators, the 2020 fall of energy prices, combined with the discovery of gas within the Turkish EEZ in theBlack Sea means there is enoughenergy in Turkey that further exploration for gas is unnecessary.^[433]

According to Greece's Foreign Minister Nikos Dendias, the disputes which are plaguing the Greek-Turkish relations for decades, can easily be resolved once Turkey accepts the United Nations Convention on the Law of the Sea (UNCLOS). To this, Dendias opined that the United States, due to their position and influence in the region, are an "ideal partner" in persuading Turkey to do so.^[434][435] Furthermore, he noted that the UNCLOS has been ratified by all the member states of the European Union, is part of the EU'sacquis communautaire, and therefore Greece's talks with EU-candidate member Turkey on the delimitation of maritime zones are bound by it.^[436] Ronald Meinardus, head of theFriedrich Naumann Foundation, analyst and author inDeutsche Welle, while commenting on the statements Dendias made during his official visit to Ankara in April 2021 about the UNCLOS being a prerequisite for joining the EU, confirmed that the Law of the Sea is a precondition for Turkey's EU membership.^[437]

• Cyprus dispute
• Cyprus–Turkey maritime zones dispute
• Exclusive economic zone of Greece
• Libya (GNA)–Turkey maritime deal
• Foreign relations of Greece
• Foreign relations of Turkey
• Imia/Kardak