How has North Atlantic Treaty Organization’s (NATO) updated strategic concept affected its involvement in the Eastern Mediterranean region, and what are the implications for Greek-Turkish relations? At the Madrid Summit held on 28–30 June 2022, NATO allies adopted an updated strategic concept. NATO’s strategic concept is the highest-level agreement establishing the Alliance’s strategic direction (Becker et al., 2022, p. 490). It is placed immediately below the North Atlantic Treaty and represents its operational view. The document outlines NATO’s purpose, core tasks, and strategy to address fundamental security risks and challenges and exploit opportunities to promote the members’ interests in a changing security environment (Simonet, 2023). The negotiation process is complicated and requires compromise among NATO members to jointly address strategic issues (Ringsmose and Rynning, 2009; Shea, 2022). Nevertheless, NATO’s strategic concept is not an action plan and does not offer policy options for its members (Tardy, 2022). Since 1949, NATO has adopted seven strategic concepts (Chiriac and Olariu, 2017; Becker et al., 2022; Michaels, 2020; Ringsmose and Rynning, 2009).

Since the annexation of Crimea in 2014, developments in the Eastern Mediterranean have become a concern for NATO (Felde, 2020, p. 59). The withdrawal of the United States from the region left a vacuum in Syria that Russia was more than eager to fill. Longstanding tensions between Türkiye and Greece, two NATO members, over maritime disputes and territorial claims are escalating due to the discovery of natural resources and Türkiye’s revisionist narrative. The Syrian Civil War has been going on for 12 years. It caused a Turkish offensive that captured part of Syrian territory and became the theatre for the most dangerous use of weapons of mass destruction in the 21st century, when the Syrian government launched three chemical weapon attacks on one village in northern Syria in March 2017 (Hubbard, 2020). Lastly, Chinese investments in critical infrastructure have transformed it into a strategic economic partner for many Eastern Mediterranean countries. So far, NATO has prioritised securing the eastern flank but has not reached a consensus in the south (Kasapoglou, 2019).

This article analyses the impact of NATO’s new strategic concept on its involvement in the Eastern Mediterranean and its implications for Greek-Turkish relations. The study aims to shed light on how NATO’s evolving strategic priorities and regional commitments have influenced its role in managing the longstanding tensions between Greece and Türkiye. By examining the Alliance’s policies, actions, and diplomatic initiatives in the Eastern Mediterranean region, the article provides insights into whether NATO’s efforts have contributed to stability or heightened the complexities of Greek-Turkish relations. Additionally, the research aims to assess the implications of these developments for regional security dynamics and the broader geopolitical landscape, offering valuable insights into the ongoing challenges and opportunities within this strategically significant area. The case study of Greek-Turkish relations is vital for two reasons. Firstly, because of NATO’s renewed interest in the region of the Eastern Mediterranean and secondly, because the complicated relationship between the two countries has the potential to disrupt NATO’s unity.

The findings of this article suggest that while NATO’s intention is to adapt the Alliance to evolving security challenges, its new strategic concept has done little to de-escalate the tensions between Greece and Türkiye. Despite the Alliance’s commitment to collective defence and conflict resolution, the longstanding disputes in the Eastern Mediterranean have persisted, often with increased intensity. The new strategic concept has not provided a comprehensive framework for addressing the complex issues at the heart of Greek-Turkish relations, such as territorial disputes, energy interests, and historical grievances. Moreover, the Alliance’s efforts have sometimes been perceived as inadequate or too diplomatic, failing to address effectively the underlying causes of tension. As a result, the tensions between Greece and Türkiye continue to simmer, occasionally erupting into crises that strain NATO’s internal cohesion and regional stability, highlighting the necessity for stronger and more proactive conflict resolution measures within the Alliance.

The Eastern Mediterranean is a strategically significant region from an international relations perspective, encompassing the eastern part of the Mediterranean Sea and the nations that surround it. This region has immense geopolitical importance due to its proximity to Europe, Asia, and Africa, serving as a crossroads of cultures, trade routes, and historical conflicts. Key countries in the Eastern Mediterranean, such as Türkiye, Greece, Cyprus, Israel, and Egypt, play pivotal roles in regional politics, energy resources, and security dynamics. The area has been marked by historical disputes over territorial claims, maritime boundaries, and access to valuable energy resources such as natural gas reserves, which have led to complex diplomatic and military tensions. Additionally, the Eastern Mediterranean is influenced by external powers, such as Russia, the United States, and European Union nations, all seeking to protect their interests and influence the regional balance of power. Consequently, the Eastern Mediterranean remains a focal point for international relations with implications for stability, security, and cooperation in the broader Mediterranean and Middle East regions (Tziampiris, 2019).

Since 2010, the region of the Eastern Mediterranean has experienced various security challenges. These challenges have become increasingly interconnected and have important implications not only for the countries of the area but also for Europe. The Arab Spring caused widespread unrest and resulted in the toppling of longstanding authoritarian regimes in North Africa. It also contributed to the disastrous civil conflict in Syria. America’s withdrawal from Iraq also left a power gap that Islamic State (IS) exploited to install a terror regime in parts of Iraq and Syria.

The discovery of hydrocarbons off the coasts of Israel, Cyprus, and Egypt has presented economic opportunities and sparked geopolitical implications. The decision of Cyprus to commence drilling for natural gas in 2011 reignited longstanding antagonisms between Türkiye, Greece, and Cyprus, who have been competing over maritime rights in the Mediterranean and Aegean (International Crisis Group, 2012) even though energy discoveries in the region are unlikely to provide energy security and transform the area into a gas exporting one (Stergiou, 2017, p. 320). These findings have led to the exploration and exploitation of offshore gas reserves, which have the potential to transform the energy landscape of the region and impact global energy markets. These hydrocarbon resources have prompted the involvement of various regional and international actors, including neighbouring countries and global powers. The discovery has generated competition and cooperation among regional states, particularly Israel, Cyprus, Egypt, and Greece. These countries have sought to develop strategic alliances, engage in energy partnerships, and safeguard their interests in the face of challenges posed by other regional actors.

Greece, in its pursuit of diplomatic initiatives in its south-eastern neighbourhood, has sought to strengthen its ties with countries in the Eastern Mediterranean and the Middle East. This includes enhanced cooperation with Egypt, Israel, and Cyprus, particularly in the energy sector. These diplomatic efforts aim to foster regional stability, advance economic interests, and counterbalance the influence of other regional powers.

The longstanding issue of Cyprus has also played a role in shaping the geopolitical landscape of the Eastern Mediterranean. The island of Cyprus has been divided since 1974, with the northern part occupied by Türkiye and the southern part governed by the internationally recognised Republic of Cyprus. The discovery of hydrocarbon resources in the region has added a new dimension to the Cyprus problem, as competing claims and interests have further complicated efforts to resolve the issue.

Türkiye, a key player in the region, has pursued a revisionist narrative that challenges the existing geopolitical order and questions the maritime boundaries and exclusive economic zones (EEZs) defined by other countries. Türkiye has engaged in assertive actions, including naval deployments and exploration activities in disputed waters, which have raised tensions and led to confrontations with neighbouring states. This has created security linkages among the Eastern Mediterranean’s Middle Eastern and European states.

In summary, the discovery of hydrocarbons, Greece’s diplomatic initiatives, developments in the Cyprus issue, and Türkiye’s revisionist narrative have collectively contributed to the formation of a distinct geopolitical space in the Eastern Mediterranean (Tziampiris, 2019; Tziarras, 2018). The competition for energy resources, strategic alliances, and disputes over maritime boundaries has intertwined regional and international interests, shaping the region’s security dynamics. Efforts to manage these challenges and promote stability are ongoing, with implications for both countries involved and wider international community.

NATO’s focus on the Mediterranean began in the 1960s with the establishment of the Expert Working Group on the Middle East and the Maghreb, and later the ad hoc group on the Mediterranean (Lesser et al., 2000). However, until the end of the Cold War, there was little common NATO policy towards the Mediterranean beyond a primary commitment to the common defence of allied territory, maritime space, and sea lanes (Dokos, 2012, p. 580). The end of the Cold War shifted the attitude of the Alliance regarding the Mediterranean region as the NATO’s (1991) new strategic concept stated the following:

At a ministerial meeting of the North Atlantic Council in December 1994, the members of the Alliance stated their willingness “to establish contacts, on a case-by-case basis, between the Alliance and the Mediterranean non-member countries to contribute to the strengthening of the regional stability” (NATO, 1994). This initiative gave birth to the Alliance Mediterranean Dialogue. This partnership forum aims “to promote regional security and stability, achieve better mutual understanding and dispel any misconceptions about NATO in participating countries” (NATO, 2022b). The current members are Algeria, Egypt, Israel, Jordan, Mauritania, Morocco, and Tunisia.

NATO’s (1999) interest in the region continued with the strategic concept of 1999. Article 38 argues the following:

Finally, the strategic concept of 2010 does not make any geographic references. However, it highlights several issues that pertain to the region of the Mediterranean, such as terrorism, protection of communication, transport and transit routes, crises and conflicts beyond NATO’s borders, and the development of friendly and cooperative relations with all countries of the Mediterranean through strengthening the Mediterranean Dialogue and the Istanbul Cooperation Initiative.

Developments in the international system, including the Russian invasion and annexation of Crimea, the instability in the Middle East and Northern Africa (MENA) region and the Asia Pacific, and the election of Donald Trump, have forced NATO to adapt its strategic foundations (Kamp, 2017). In response to Russia’s annexation of Crimea, NATO initiated a “strategic reset” during the Wales Summit in 2014 (Olsen, 2020). Subsequently, in December 2019, the secretary general of NATO extended an invitation to alliance leaders to present a “Council-agreed proposal for a forward-looking reflection process” expertise to further strengthen NATO’s political dimension, including consultation (NATO, 2019, p. 7) aimed at improving NATO’s political dimension through consultations and relevant expertise. The negotiation process was further complicated by President Trump’s criticism and scepticism towards NATO (Larsen, 2022). The new concept was drafted at the 2021 summit in Brussels (Simonet, 2023). NATO leaders stipulated that the text “will be negotiated and agreed by the Council in Permanent Session and endorsed by NATO leaders at the next Summit” (NATO, 2021). The 2010 strategic concept, as proposed in the “NATO 2023” report, was highlighted as an opportunity to solidify cohesion by addressing emerging strategic realities and recent unifying adaptations in a coherent strategic framework (NATO, 2020b, p. 12).

“The Euro-Atlantic area is not at peace” (NATO, 2022c, p. 3)—paragraph 6 of NATO’s new strategic concept reflects the realities of the European security order following the invasion of Ukraine by Russia. The narrative of NATO’s updated strategic concept is consistent with the resurgence of great power politics and their potentially disruptive role in the international system. The document underscores the threat of Russia’s expansionism and China’s subversive tactics (NATO, 2022c). It highlights the likelihood of an attack against an allied country, although it does not seek confrontation with Russia. NATO’s core tasks remain consistent with its mission as a defensive alliance. However, the language of NATO’s new strategic concept is significantly different. The document emphasises the intent of NATO to employ military equipment to respond to security threats and argues that NATO must expand its presence.

In the context of NATO, Greek-Turkish relations have been marked by tensions and challenges, often affecting the Alliance’s unity. The disputes between the two countries have historical, territorial, and security dimensions that complicate their relationship. Turkish revisionism includes violations of Greek airspace, refusal to submit the delimitation dispute regarding the Aegean continental shelf to the International Court of Justice, a casus belli if Greece extends its territorial waters from 6 to 12 miles, and challenges to the Aegean status quo as codified by several international treaties (Tsakonas and Tournikiotis, 2003, p. 305). Greece’s approach regarding Türkiye’s threat has involved strengthening its armed forces and participating in international institutions, such as NATO, the Western European Union, and the EU. Greece expected that NATO would take an active role in the Greek-Turkish conflict, otherwise it would be considered implicitly supportive of the stronger party in the conflict (Moustakis and Sheehan, 2000, p. 99).

Both countries joined NATO in 1952, assuming their membership would pacify their behaviour towards each other (Dempsey, 2020). Greece hoped that NATO participation would balance Türkiye’s aggressive behaviour (MacKenzie, 1983). During the Cold War era, the priority of NATO was to contain Soviet communism. Therefore, the alliance did not emphasise the resolution of territorial disputes among members as a necessity for their membership. The accession of Türkiye and Greece related to their strategic and military contributions to the interests of the Alliance vis-à-vis the Soviet Union. The Soviet threat made western and central Europe a priority for NATO. Therefore, the Alliance could not take action in resolving the Greek-Turkish disputes, given the strategic limitations of the Cold War era. Only when the Greek-Turkish disputes had implications for the struggle against the communist threat did Washington act as a mediator (Slengesol, 2000, pp. 127–129). The most pressing concern for the United States was to avoid a Greek-Turkish conflict and to prevent Soviet attempts at meddling in any intra-NATO dispute (Wilkinson, 2000).

The two countries came very close to a full-blown war in 1974 when Türkiye invaded Cyprus and annexed the island’s northern part. The US involvement did manage to de-escalate tensions between the two countries, although it left the Greek side disappointed (Warner, 2009, p. 141); Greece withdrew from NATO’s military command structure and sought closer relations with the Soviet Union (United States Department of State, 1978). In response to the invasion, the United States imposed a 3-year arms embargo on Türkiye (United States Department of State, 1975). Greece repeatedly proposed a bilateral nonuse-of-force pact, which the Turkish side rejected. This reinforced Greece’s perception that given the opportunity, Türkiye would not hesitate to use military force against a fellow NATO member (Valinakis, 1994).

The end of the Cold War created expectations that NATO, free from the constraints of the bipolar international system, would adopt a more comprehensive role in resolving the Turkish-Greek disputes. However, the expectations of the post-Cold War era did not materialise for several reasons. In the aftermath of the dissolution of the Soviet Union, NATO’s objective was to expand and include the former communist republics to enhance its presence on the European continent. Therefore, extending security guarantees to troubled areas such as the Eastern Mediterranean was not a priority. NATO aspired to become a pan-European cooperative security organisation, which reduced the attention it paid to Turkish-Greek relations (Oğuzlu, 2004, p. 468).

Secondly, the enlargement of the EU challenged the dominant position of NATO regarding conflict resolution. During the post-Cold War era, NATO lost its status as the only European security organisation (Aybet, 2000). Greece and Türkiye opted for European engagement, although only the former became a member. Greece’s intent was consistent with its foreign policy objective of “external balancing,” becoming affiliated with west European security and political organisations to promote its security interests (Tsakonas and Tournikiotis, 2003, p. 305).

Thirdly, following the end of the Cold War, NATO became increasingly ‘Americanised’ (Oğuzlu, 2004, p. 468). Most of the decisions taken by NATO regarding the accession of new members, the missions and strategic focus of the alliance, and its geopolitical boundaries mainly reflected the interests of the successive US governments in the 1990s (Croft, 2000; Layne, 2000; Sloan, 1995). This process enhanced its presence on the European continent and maintained significant influence over members of the EU. By contrast, the impact of NATO’s ‘Americanisation’ on Greek-Turkish relations had differing interpretations. On the one hand, while NATO’s Eastern enlargement diminished Türkiye and Greece’s relative position in the Alliance, the outbreak of the Yugoslavian civil conflict and the overall tensions in the Balkans throughout the 1990s made it clear that Turkish-Greek relations could affect the performance of NATO. Both countries avoided engagement in the bombing campaign against Serbian forces in Bosnia (Binder, 2012, p. 96). On the other hand, the more “Americanised” the Alliance became, the more difficult it was for Türkiye and Greece to achieve a collective identity within NATO (Oğuzlu, 2004, p. 468).

In January 1996, the two countries came very close to a direct conflict that was averted at the very last minute by the intervention of the United States. Türkiye laid claim to the small islet of Imia in the eastern Aegean. Greece responded to the provocation by mobilising its navy, and a military standoff developed between the two countries. The Clinton Administration acted as the mediator between the two countries and managed to broker an agreement by removing the armed forces of both countries from the islet. Even today, Türkiye contests the status of the islet (Raftopoulos, 1997, 2000). A meeting at the NATO summit in Madrid in July 1997 between Greek Prime Minister Costas Simitis and Turkish President Suleyman Demirel improved relations. The two leaders signed a communiqué, outlining their willingness to pursue efforts to promote bilateral cooperation (Bohlen, 1997). Unfortunately, the progress made during the Madrid summit came to a grinding halt a few months later.

At the European Council summit in Luxembourg in December 1997, the EU set a condition for Türkiye’s accession, which involved improving its relationship with Athens. Türkiye protested the imposition of conditions that did not apply to other EU candidates (Ker-Lindsay, 2000, pp. 216–217). At the same time, Cyprus’s decision to order S-300 Russian anti-aircraft missiles threatened to escalate the Greek-Turkish dispute. Prime Minister Tansu Ciller threatened to destroy the missiles (Brey, 1999, p. 115). The crisis was resolved following pressure from the EU that the installation of the S-300 missile system would complicate Cyprus’s accession process (Drake, 1998) and Greece’s concerns that any further destabilisation in its relations with Türkiye could have harmed the prospect of implementing the single European currency (Ker-Lindsay, 2000, p. 218).

The relationship between the two countries improved significantly in the late 1990s. Three factors contributed to the rapprochement between the two countries—the “Ocalan Affair,” “earthquake diplomacy” (Evin, 2005, pp. 396–398; Larrabee, 2012, p. 473), and the prospect of Türkiye’s accession to the EU (Aydin and Acikmese, 2007, p. 263). Abdullah Ocalan was the leader of the Kurdistan Workers’ Party and was considered a terrorist by Turkish authorities. He was smuggled into Greece and then given sanctuary at the Greek Embassy in Nairobi. The revelation caused shock waves in the Greek government and led to the dismissal of several high-ranking officials, including Foreign Minister Theodoros Pangalos (Stanley, 1999).

In August 1999, Türkiye was hit by a devastating earthquake that killed more than 2,100 people (Andrews, 1999). A few weeks later, Athens was hit by a smaller, albeit deadly, earthquake that claimed the lives of 143 people (Associated Press, 1999). The two countries sent relief teams to assist the victims of the earthquake. This helped break down old stereotypes and allowed each side to view the other in humanitarian terms, rather than as an enemy (Kinzer, 1999). Following the earthquake, Greek-Turkish relations gained new political momentum. As part of its new engagement policy, Greece abandoned its efforts to prevent Türkiye from joining the EU and became one of the strongest supporters of Türkiye’s EU membership. This political change assumed that a more “European” Türkiye was in the long-term interest of Greece and would facilitate the resolution of outstanding issues. Türkiye’s Europeanisation process could influence officials and the government to endorse political values (Evin, 2004, p. 17). Nevertheless, despite the positive climate between the two countries, the European prospect of Türkiye would inevitably be hindered by two longstanding issues, the Aegean Sea and the Cyprus disputes (Önis, 2001, p. 31).

Despite the steady improvement in relations between both countries, the issue of the Aegean continued to create significant tensions, which spilled over to NATO. In 2007, Türkiye objected to Greece’s inclusion of airspace over Agios Efstratios in the Noble Archer exercise, arguing that its proximity to Limnos made it a demilitarised zone. The exercise was cancelled in 2007 but took place in 2008 over Turkish objections (Larrabee, 2012, p. 474). In October 2009, George Papandreou was elected prime minister and many hoped that Greek-Turkish relations would improve. The time seemed correct. Papandreou had a large majority in parliament, an advantage that his predecessor, Costas Karamanlis, did not have, and he was highly respected in Ankara because he played a vital role at the beginning of reconciliation with Türkiye in 1999. Türkiye also showed interest in improving relations. Prime Minister Recep Tayyip Erdogan sent a letter to Prime Minister Papandreou, outlining that Ankara was ready to discuss initiatives to improve bilateral relations (Gazetesi, 2009). In 2010, the President of Türkiye also visited Greece for the second time since 2004 and held a joint cabinet meeting with its Greek counterparts (Smith, 2010).

In 2011, Greece was experiencing the first signs of a debt crisis that threatened to bankrupt the country and caused significant strife with the EU and the Troika. Because of budgetary constraints, Greece reduced its participation in NATO and EU military missions (TA NEA, 2011). Similarly, Türkiye criticised NATO’s excessive reliance on force in Afghanistan and proposed to open a diplomatic mission with the Taliban as a fellow Muslim country (McElroy, 2008). During NATO’s operation in Libya in March 2011, Greece and Türkiye adopted a similar stance. To enforce the no-fly zone over Libya, Greece allowed NATO planes to use air space and permitted the US Navy to deploy ships from its Souda Bay base on Crete. Türkiye sent four frigates and a submarine to join alliance patrols but vowed to refrain from using force against Libyan people (France 24, 2011).

One key factor shaping Greek-Turkish relations during this period was the exploration and exploitation of energy resources in the Eastern Mediterranean. The discovery of significant natural gas reserves in the region led to competition over territorial claims and maritime boundaries between Greece, Cyprus, and Türkiye. This increased tensions and caused a series of incidents, including naval standoffs and airspace violations (Grigoriadis, 2014, p. 124). The unreliability of Russia as an energy partner has raised concerns among European leaders since 2005. When Russia turned off gas supplies to Ukraine in 2006, American and European officials called for a more prominent role for NATO in Europe’s energy security (Monaghan and Coops, 2006). With regard to the Greek-Turkish case, because the latter aspires to transform itself into an energy hub and supplier to Europe, NATO can become an institutional bridge between the EU and Türkiye.

The Eastern Mediterranean region has significant potential for fossil fuel development, and member states of the East Mediterranean Gas Forum (EMGF) have established joint ventures for exploration, drilling, pipeline construction, and liquified natural gas export (Ellinas, 2022). NATO recognises the importance of energy security for the collective security of its members and partners. The alliance focuses on protecting critical energy infrastructure, maintaining strategic awareness of energy developments, and ensuring reliable energy supplies to the military (NATO, 2022a). The new strategic concept acknowledges energy security as vital in a challenging strategic environment, emphasising the need for stable and reliable energy supplies.

In the context of the Eastern Mediterranean, NATO’s role includes integrating energy security into policies, exercises, and training. The alliance aims to enhance energy security, counter cyber-attacks, and prevent energy manipulation (NATO, 2022a). Given the geopolitical challenges and tensions in the region, NATO’s unity of effort and interoperability are crucial in defending against hybrid attacks on energy infrastructure (Dupuy et al., 2021). The Alliance promotes dialogue, information-sharing, and critical energy infrastructure protection. It emphasises the importance of diversification of resources and transportation routes to enhance energy security. Lessons learned from energy security efforts in south-eastern Europe are valuable for other regions facing similar challenges (NATO, 2022a).

Since 2015, Russia has adopted a more assertive role in the Eastern Mediterranean. Russia has tried to elevate its status in the Eastern Mediterranean through a new maritime strategy (Litsas, 2017, p. 57) This is part of Russia’s longstanding goal to undermine the cohesion of NATO and the EU and hinder the ability of the West to formulate policy (Stronski, 2021). Russia’s tactics include increasing dependency on Russian gas and money in countries of the region, cultivating governing elites, and hindering NATO’s and the EU’s ability to expand. Greece, Türkiye, and Cyprus are the most vulnerable countries to Russian influence and Russia’s appeal to these countries relates to cultural, economic and foreign policy considerations.

Russia’s reasons for cultivating a stronger relationship with these countries were threefold. Firstly, Russia wanted to take advantage of their membership of the EU and NATO in order to influence European policymaking and NATO expansion (Stronski, 2021). Secondly, these countries suffered a period of economic depression as a result of economic crisis, and Russia wanted to appear as a potential economic partner, particularly in the energy sector. Finally, a close relationship would allow Russia to increase its standing in the region and allow it to take part in any discussions regarding the future of the region.

In 2016, NATO established a standing maritime force in the Eastern Mediterranean, known as the Standing NATO Maritime Group 2 (SNMG2). Its primary objective was to enhance the Alliance’s situational awareness and demonstrate its regional presence (NATO, 2023). SNMG2 conducted regular patrols and exercises to maintain stability and prevent escalations between Greece and Türkiye. However, despite these efforts, tensions continued to simmer, with occasional flare-ups.

One of the significant incidents during this period was the 2018 Imia crisis. It involved a dispute over a pair of uninhabited islets in the Aegean Sea claimed by both Greece and Türkiye. The crisis escalated when a Turkish coastguard vessel rammed a Greek patrol boat near the islets, raising concerns about a potential military confrontation (Kathimerini, 2018). NATO played a role in de-escalating the situation through diplomatic channels and promoting dialogue between the two countries through a de-conflicting mechanism.

In addition to the Eastern Mediterranean disputes, the migration crisis was another critical issue affecting Greek-Turkish relations. As a frontline EU member state, Greece faced a significant influx of migrants and refugees, many of whom arrived via Türkiye. This strained Greece’s resources and infrastructure and further complicated the bilateral relations between Greece and Türkiye. NATO’s (2016) involvement in the migration issue included deploying naval assets to support Greece in border protection and surveillance operations.

Despite these challenges, there were also instances of cooperation and dialogue between Greece and Türkiye within the NATO framework. For example, both countries participated in joint military exercises and training activities to enhance interoperability and build confidence between their armed forces. These initiatives contributed to maintaining open lines of communication and fostering a sense of shared security among NATO allies.

In July 2019, Türkiye received the S-400 missile defence system, which was incompatible with NATO’s systems. NATO does not ban the purchase of military hardware from manufacturers outside the American-led alliance but does discourage members from buying incompatible equipment (Gall and Higgins, 2017). Regardless of whether NATO banned the purchase of the S-400 missile defence, Türkiye’s actions represented a direct challenge to the alliance and reinforced the idea that Türkiye was slowly withdrawing from the North Atlantic Alliance and the EU. Nevertheless, scholars have argued that the prospect of Türkiye and Russia forming a strategic partnership is difficult for a variety of reasons, such as divergence over geostrategic issues, Russia’s weakened economy, their incompatible political systems, and NATO’s security umbrella (Bardakçı, 2021, p. 554).

Tensions between Greece and Türkiye escalated in 2020. Türkiye sent a seismic research vessel accompanied by warships into waters claimed by Greece and Cyprus, sparking a diplomatic crisis involving several EU countries and the United States. NATO (2020a) intervened to establish a de-confliction mechanism between the two allies and facilitated technical dialogue. However, the talks produced no breakthroughs and were suspended in 2021. In 2022, Türkiye accused Greece of locking Turkish fighter jets with its Russian-made S-300 anti-aircraft missile systems deployed on the island of Crete. Greece denied the allegations and accused Türkiye of violating its airspace. Both countries lodged complaints with NATO, which urged them to resolve their differences diplomatically.

Two serious issues developed concerning safeguarding Greece’s positions and the “solid-front” image of NATO that is important amid Ukraine’s war. Firstly, regions of the Aegean are shut out of the necessary joint military exercises due to the boundaries Türkiye is putting forward. However, this renders NATO hostage to Ankara’s “blackmail” policy, which serves only Türkiye’s interests and not the Alliance’s. The Luns Rulings, based on which NATO must remain strictly neutral between Greece and Türkiye, did not favour Türkiye and its revisionism and also undermined the Alliance’s unity and effectiveness. A characteristic example is Lemnos, with its strategic importance to the Turkish straits, the Black Sea and Russia. Nevertheless, it would enter into NATO planning only in the event of war, since Türkiye insisted that it is excluded. This leads us to the second problem, Greece’s relationship with the Alliance. Athens satisfies the prerequisites for membership; it meets its obligations and contributes to the security of the Alliance, most saliently through its clear stance on the war in Ukraine. However, on the other hand, it is not covered by the provisions of Article 5 of the Alliance, given that the greatest threat to its territorial integrity and sovereignty comes from another member of NATO. Consequently, the problem for Greece is not its disputes with Türkiye, because it does not expect NATO to take on the role of mediator. However, simultaneously, a conscientious and reliable partner cannot feel unprotected due to the choice and policy of “equal distances” maintained by NATO. The latter’s contribution to easing tensions and de-escalating situations could play a more active and substantial role in monitoring the situation through a de-conflicting mechanism. Even some aeronautical confidence-building measures between Greece and Türkiye could take place through NATO’s involvement. However, the focus has to be on deactivating the tensions, rather than deactivating the correct positions of one member state, Greece, for the sake of another, Türkiye, regardless of the latter’s importance.

In conclusion, NATO’s new strategic concept acknowledges the burgeoning complexities in the Eastern Mediterranean. Yet, it falls markedly short of introducing effective measures to de-escalate the longstanding tensions between Greece and Türkiye. While the document perceptively addresses the need for heightened engagement in the Eastern Mediterranean and highlights the myriad security challenges, including territorial disputes, migration issues, and the competition for energy resources, it lacks a clear actionable framework for mitigating the discord between these two member states.

Greek-Turkish relations have historically been fraught with challenges; however, recent developments in the Eastern Mediterranean have further strained these ties. Both countries have divergent interests and claims concerning maritime boundaries and energy exploration rights. The discovery of hydrocarbon reserves has intensified these disputes, bringing them to the forefront internationally. Despite these escalating tensions and their potential threat to regional stability, NATO’s new strategic concept seems more a reflection of the broader strategic environment, rather than a blueprint for conflict resolution between its member states.

One of the underlying issues is that NATO, while emphasising collective defence and security, often hesitates to intervene decisively in disputes between its member states, traditionally relying on bilateral mechanisms and international diplomatic efforts outside the NATO framework for resolution. This approach, unfortunately, can be perceived as a failure to take direct responsibility for inter-member conflicts, thereby allowing Greek-Turkish tensions to simmer, potentially destabilising the Alliance’s southern flank.

Furthermore, the new concept does not adequately address the asymmetry in threat perceptions among its member states. Greece and Türkiye have competing regional interests and varying perspectives on what constitutes a security threat, which complicates the possibility of a unified or effective response strategy within NATO’s framework.

In light of the above, NATO should consider a more robust and proactive approach to diplomatic engagement between Greece and Türkiye. This might involve intensified diplomatic mediation, confidence-building measures, and leveraging the full potential of its partnership tools to encourage cooperation and dialogue. As it stands, the new strategic concept, while aware of the issues in the Eastern Mediterranean, has not met the urgent need for a comprehensive strategy to de-escalate Greek-Turkish tensions, thereby representing a missed opportunity for the Alliance to bolster its relevance and cohesion in a rapidly changing security environment.