Greece vs. Turkey: How Close is the Region to an Article 5 Moment?
Overview
In mid-September 2025, Turkey announced a controversial naval survey in disputed Aegean waters, prompting Greece to launch large-scale military exercises. This confrontation underscores how the Eastern Mediterranean has become one of Europe’s most volatile regions. Moreover, tensions over maritime boundaries, exclusive economic zones (EEZs), and contested airspace rights remain unresolved.
Frequent airspace violations by Turkey and naval encounters near Greek islands further intensify mistrust, raising the risk of accidental escalation. With both countries bound as NATO allies, a pressing question emerges. Could a Greece vs. Turkey Dispute trigger NATO’s Article 5 collective defense clause?. Exploring this requires understanding Article 5’s scope and relevance today.
What is Article 5 of NATO?
Article 5 of the Washington Treaty (1949) is the foundation of NATO’s collective defense, ensuring unity among member states during conflict. It states that an armed attack against one or more members in Europe or North America will be considered an attack against all.
If such an attack happens, each NATO country agrees to take necessary actions, including military force, while cooperating with others to ensure stability. Through this principle, NATO members maintain shared security and demonstrate solidarity, reinforcing that no single nation stands alone against aggression or external threats.
Historical Instance of Invocation of Article 5
Article 5 has been invoked only once in NATO’s history. This occurred after the September 11, 2001 terrorist attacks in the United States. In response, NATO launched operations including Operation Eagle Assist (air surveillance over the U.S.) and Operation Active Endeavour (naval operations in the Mediterranean) as part of its collective defense measures.
Before we examine whether a Greece-Turkey dispute could trigger Article 5 or not, let’s first look at the key flashpoints that fuel tensions between the two countries.
Greece vs. Turkey Dispute: Key Flashpoints
The Greece-Turkey disputes revolve around historical, territorial, and strategic issues, which manifest in several critical flashpoints such as:
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Territorial Waters and EEZs : One of the biggest flashpoints is the disagreement over how far each country’s territorial waters and Exclusive Economic Zones (EEZs) extend in the Aegean and Eastern Mediterranean. Greece seeks to exert its maritime boundaries, while Turkey rejects this move, fearing loss of influence over sea routes and energy resources.
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Airspace and Military Encounters : Greece claims 12 nautical miles of airspace (as per the 1982 UN Convention on the Law of the Sea, UNCLOS), but Turkey recognizes only 6 miles, and calls this as “casus belli” (cause for war). This leads to frequent airspace violations and dangerous military encounters. These aerial tensions often raise the risk of accidents and escalation.
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Cyprus Dispute : In addition, the long-standing division of Cyprus remains a central issue. Greece supports the democratic Republic of Cyprus, while Turkey backs the Turkish Cypriot north (predominantly Sunni Muslim) , maintaining troops on the island.
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Regional Alliances : Greece has strengthened ties with the EU, U.S., India and Israel, while Turkey builds partnerships with Qatar, Pakistan and other regional powers, making the rivalry part of a broader geopolitical contest.
Now that you know the reasons behind the disputes between Greece and Turkey, it is also important to understand their military and air power comparison. This is crucial because these capabilities could escalate tensions if the situation worsens in the future.
Comparison of Greece and Turkey based on Naval and Air Power
When comparing the military strength of Greece and Turkey, both nations show significant capabilities, but Turkey holds a noticeable advantage in several areas. Looking at naval power, Greece maintains 192 total naval assets, including 13 frigates and 11 submarines, supported by 28 maritime aircraft.
However, Greece has no corvettes in its fleet, which limits its flexibility at sea. In contrast, Turkey has 182 naval assets, but these include a more diverse fleet with 17 frigates, 13 submarines, 60 maritime aircraft, and 9 corvettes, giving it broader operational capacity in the Mediterranean and Aegean Seas.
Turning to air power, Greece fields 690 aircraft overall, consisting mainly of fighter jets, helicopters, and AWACS units. Although this is a considerable number, Turkey surpasses it with 1,070 aircraft. This includes not only fighters and AWACS but also a much larger fleet of helicopters and UAVs, strengthening its surveillance and strike capabilities.
Overall, while Greece’s naval forces remain strong, especially with its submarines, Turkey’s combination of larger air force, diversified naval fleet, and drones provides it with a strategic edge. This comparison highlights the balance of power in the region and the ongoing rivalry between these NATO allies. Now coming back to our main question :
Can Article 5 Apply Between NATO Members Greece and Turkey?
Article 5 of NATO’s founding treaty commits allies to mutual defense, stating that an armed attack against one member is considered an attack against all. However, its application between NATO members is complex. If one member attacks another, Article 5 does not automatically apply. Instead, the alliance would likely invoke Article 4, which allows for consultations among members. In such a scenario, NATO members would decide collectively on appropriate actions. It may include diplomatic measures, sanctions, or military responses, depending on the circumstances.
This framework underscores NATO’s commitment to collective defense while acknowledging the need for careful deliberation in intra-alliance conflicts.
How a NATO ally could seek help
If Greece or Turkey felt threatened by one another, the more likely path would be invoking Article 4, which has been used multiple times.
Article 4 consultations: This clause allows any member to call a meeting of the North Atlantic Council to discuss a perceived threat to its security. This is a diplomatic step that does not carry the same military weight as Article 5 but provides a forum for addressing tensions within the alliance.
What scenarios should NATO consider in the ongoing Greece Turkey dispute?
The data shows a dramatic rise in airspace violations between Greece and Turkey, peaking at 11,000 in 2022 before sharply declining to 1,100 in 2023. This fluctuation highlights escalating tensions, territorial disputes, and regional security challenges in the Eastern Mediterranean. Therefore, NATO must carefully consider potential scenarios in the ongoing Greece-Turkey dispute, as stability in this region directly impacts its collective security and strategic cohesion.
- Conflict De-escalation Mechanisms: Strengthen dialogue channels, hotlines, and confidence-building measures to reduce risks of accidental military confrontation.
- Maritime Security Framework: Implement joint patrols and monitoring systems to manage contested airspace and Exclusive Economic Zones (EEZs).
- Regional Stability Strategy: Promote mediation efforts involving the EU and UN to balance energy security interests with sovereignty claims.
- Military Readiness: Maintain rapid-response forces to deter aggression while avoiding overt favoritism toward either ally.
- Diplomatic Engagement: Foster sustained negotiations that prioritize peace, cooperation, and collective defense principles.
Web Resources on Greece-Turkey Dispute
1. Gjia.georgetown.edu: Rapprochement Between Greece and Türkiye
2. Mfa.gov.tr: Relations between Turkey and Greece
3. BBC.com: Greece announces military boost
4. Nytimes.com: There’s a New Game of Thrones in the Mediterranean
5. Globalfirepower.com: Greece and Turkey Comparison
6. Greece and India conduct joint naval exercise, Greek City Times
Final Words
In conclusion, while Greece and Turkey remain NATO allies, their ongoing disputes over maritime boundaries, airspace, and regional influence highlight significant security risks. Although Article 5 is unlikely to apply directly between them, NATO’s role in conflict prevention and collective defense remains crucial.
By focusing on diplomatic engagement, conflict de-escalation, and regional stability measures, the alliance can manage tensions. This approach ensures that Eastern Mediterranean security and strategic cohesion are maintained without triggering intra-alliance military escalation. Please share your thoughts below in the comment section and help us to make this article better. Thank you for reading!
Questions and Answers related to Greece and Turkey Dispute:
Modern Greece-Turkey relations originate in the collapse of the Ottoman Empire and the 19th-20th century nationalisms, culminating in the 1919-1922 Greco-Turkish War and the 1923 Treaty of Lausanne. Territorial shifts, population exchanges, Cyprus division (1974), and divergent NATO roles have shaped enduring bilateral rivalry despite periodic diplomacy and economic ties. Geopolitical competition over maritime zones and regional influence persists today.
Primary issues include maritime boundaries, continental shelf and EEZ delimitation in the Aegean and Eastern Mediterranean, airspace and flight-control disputes, sovereignty and demilitarisation of islands, and Cyprus’s division. Competing hydrocarbon exploration and unilateral maritime plans have heightened tensions, producing diplomatic protests, NATO friction, and recurring crisis diplomacy. Naval confrontations underscore unresolved legal and strategic disagreements with talks intermittent and fragile.
Greek-Turkish conflicts arose from Ottoman decline, competing nationalisms, and territorial claims. The 1919-1922 Greco-Turkish War, driven by Greek irredentism and Allied post-WWI settlement failures, culminated in the 1923 Treaty of Lausanne and a mass population exchange. Subsequent disputes, notably Cyprus (1960s–1974) and Aegean sovereignty reopened grievances, refugee trauma, and military tensions that persist and shaped modern regional rivalry.
India does not officially take sides in Greece-Turkey disputes but has strengthened bilateral ties with Greece, including defense and diplomatic cooperation and support for Greece’s UNSC ambitions. Recent 2025 tensions with Turkey over India-Pakistan hostilities cooled India–Turkey relations, producing public boycotts and diplomatic friction; nonetheless New Delhi maintains calibrated, issue-based diplomacy while maintaining strategic autonomy and selective economic engagement policies.
The Aegean dispute revolves around conflicting claims over territorial sea breadth, EEZ/continental shelf delimitation, sovereignty of islands and islets, and airspace. Greece’s islands generate maritime entitlements; Turkey argues full island-based claims would enclose its access. Competition for hydrocarbon resources, fisheries and strategic sea lanes intensifies tensions, making legal arbitration, bilateral talks, or EU mediation key resolution pathways yet progress remains.
The Turkey-Greece conflict stems from disputes over Cyprus, Aegean Sea boundaries, maritime rights, and airspace violations. Tensions intensified after the 1974 Cyprus crisis and continue with disagreements on Exclusive Economic Zones (EEZs). Both NATO members, they have narrowly avoided clashes multiple times, reflecting deep-rooted nationalism, historical rivalries, and geopolitical competition over Mediterranean resources and security dominance.
Public opinion in both Turkey and Greece often reflects distrust shaped by history, nationalism, and ongoing disputes. Surveys show Greeks view Turkey as a security threat, while many Turks perceive Greece as an obstacle to regional influence. Yet, cultural exchanges, tourism, and diplomacy occasionally ease tensions, proving that people-to-people ties can remain resilient despite political disagreements.
A Greece-Turkey clash would not automatically trigger NATO’s Article 5. Since both nations are members, NATO avoids internal disputes. Article 5 requires external aggression, not intra-alliance conflicts. In practice, NATO would prioritize mediation and de-escalation to prevent destabilization in the Eastern Mediterranean, where regional security, energy exploration, and EU interests are deeply interconnected and geopolitically sensitive.
NATO should emphasize de-escalation mechanisms, confidence-building measures, and mediation platforms between Greece and Turkey. Deploying maritime monitoring missions, facilitating dialogue on airspace violations, and engaging the EU on energy disputes can reduce tensions. A balanced strategy prevents further militarization, protects NATO’s southern flank, and ensures focus on wider security challenges like Russia’s posture and Middle East instability.
Article 5 is designed for collective defense against external aggression, not intra-alliance disputes. A Greece-Turkey clash falls into a gray zone, making invocation unlikely. NATO members prefer diplomatic pressure, dialogue, and crisis management to preserve unity. Triggering Article 5 could undermine alliance credibility, divide members, and distract from broader security threats like Russian aggression or terrorism.
NATO should prepare for limited naval or airspace incidents escalating into broader military confrontation. Such clashes could threaten Mediterranean energy routes, EU borders, and alliance stability. Preventive measures include joint maritime patrols, hotlines between Athens and Ankara, and pre-agreed deconfliction protocols. Preparing for hybrid warfare, cyberattacks, and misinformation campaigns is equally vital to regional security resilience.
Cyprus conflict stems from competing nationalisms, the 1960 independence settlement, and the 1974 coup and Turkish intervention that partitioned the island. Key drivers: competing sovereignty claims, security guarantees, property and refugee disputes, and contested maritime rights and energy resources. Reunification talks and UN mediation have failed to resolve political representation and territorial adjustments between Greek Cypriots and Turkish Cypriots today.