Since February 2022, the strategic centre of the North Atlantic Treaty Organisation (NATO) has moved decisively eastward. The Madrid and Vilnius summit declarations, the accessions of Finland and Sweden, the Permanent Structured Cooperation arrangements, and the forward-deployed brigades in the Baltic states represent the alliance’s most significant reorganisation since the end of the Cold War. Each step has been necessary, and proportionate to Russia’s aggression against Ukraine.
The corollary has been less visible. NATO’s attention to its southern flank has quietly diminished. No coherent doctrine for the eastern Mediterranean has emerged from recent summits, with the most recent one in Ankara settling this point. The strategic terrain in the region is shifting in ways that the alliance is barely tracking, and the United Kingdom (UK), whose most enduring forward presence sits in that theatre via the Royal Air Force (RAF) air stations on Cyprus, has not articulated a contribution to closing the gap, despite the Sovereign Base Areas giving it a permanent operational stake in the region that no other alliance member matches.
Post-Brexit, Britain has bilateral flexibility in the region that European Union (EU) member states do not, being able to develop relationships without European-level coordination. The UK-Greece Strategic Bilateral Framework and bilateral engagement with Egypt indicate that this flexibility is being used. What has not yet been built is the strategic framework that would unify these relationships into a coherent regional posture.
The Turkish factor
Turkey’s autonomous strategic posture means that NATO planning cannot assume Ankara’s alignment on regional issues. For years, tension was expressed in the air, with airspace violations over the Aegean and periodic simulated dogfights between Greek and Turkish aircraft. However, the 2023 Athens Declaration on Friendly Relations and Good-Neighbourliness established a bilateral framework for managing disputes, and the reduction in incidents since has been marked. The improvement is real, but also bilateral, resting on the political will of two administrations and unaccompanied by any alliance-level mechanism. The underlying disagreements over the continental shelf, Cyprus, and hydrocarbon rights remain unresolved, and NATO has developed no means of addressing them should the present détente falter.
This autonomy should not be mistaken for distance from Washington. Turkish bilateral standing with the United States (US) is presently rising rather than falling. That is a reasonable return for a state which has carried significant alliance burdens in Syria and acted as mediator in Gaza and Iran, but it carries a structural consequence: a Turkey whose interests are well served bilaterally has correspondingly less incentive to invest in multilateral southern flank frameworks. The task is therefore to make such frameworks worth Turkey’s participation, rather than to lament their absence.
Britain’s tripartite contribution
A British contribution to the southern strategy missing from NATO doctrine would have three pillars. The first is a UK-led trilateral with Egypt and Greece on Suez-Red Sea maritime security. Egypt holds the Suez Canal; Greece holds the EU’s southeastern maritime frontier and the partnership with Cyprus; and Britain holds the Sovereign Base Areas and operational naval capacity demonstrated through recent Red Sea deployments. A formal annual trilateral summit, permanent working group on maritime security, and joint exercises drawing on each nation’s naval and air assets would bind these three states into a regional security architecture that none of them can build alone.
Such a framework must also reckon with the Turkish Straits. Turkey controls the Bosphorus and the Dardanelles, and exercises that control under the 1936 Montreux Convention, affording Ankara a legally recognised custodial role over Black Sea access. It exercised that authority in 2022, determining that Article 19 of the Convention was engaged by Russia’s full-scale invasion of Ukraine, and restricting the transit of belligerent warships accordingly.
A trilateral treating Turkish cooperation as incidental would be attempting basin-wide maritime security while disregarding one of its two principal gateways. Sequencing matters more than initial membership: a working UK-Egypt-Greece format that demonstrates value, and to which Turkish participation on Straits and wider maritime security is subsequently extended, is more achievable than a four-way negotiation begun cold. Britain is uniquely well-placed to manage that sequence.
The second contribution is deeper naval cooperation with the Greek and Cypriot navies. This would encompass joint exercises building on the existing UK-Greece Strategic Bilateral Framework, intelligence sharing on Russian and Chinese naval movements in the basin, and formalised basing access. Bilateral defence relationships already exist. What is missing is the operational tempo that turns bilateral cooperation into regional deterrence.
The third British contribution is treating the eastern Mediterranean energy axis as a strategic concern, not a commercial one. The natural gas politics of the eastern basin involve EU member states, an alliance member excluded from the consortium and contesting its maritime legal basis (Turkey), and Israeli onshore infrastructure that is increasingly subject to threat. A British role in convening East Mediterranean Gas Forum security discussions, and in deploying Royal Navy capability to protect undersea infrastructure, would extend NATO’s southern flank doctrine into a domain where the alliance has had no operational role. The precedent already exists in the BALTIC SENTRY mission, established in January 2025 after a sequence of cable-cutting incidents in the Baltic Sea. The Mediterranean equivalent has not yet been built.
The southern flank after Ankara
The Ankara summit’s outcomes bear directly on the argument presented in this article. The six-paragraph Ankara Summit Declaration reaffirms Article 5 and the 360-degree approach to deterrence. It records 2025’s defence investment commitment from The Hague, announces more than US$50 billion (£37.5 billion) in new procurement, and pledges €70 billion (£59.8 billion) in military support to Ukraine for 2026. It states that Iran must never acquire a nuclear weapon, and calls for freedom of navigation to be respected in the Strait of Hormuz. It does not mention the eastern Mediterranean.
The omission is all the more striking considering where the summit was held. Ankara is the capital of NATO’s principal Mediterranean power, and the Declaration’s only maritime security commitment concerns the Strait of Hormuz rather than the basin in which two alliance members contest each other’s continental shelf. NATO has found language for freedom of navigation in the Gulf, but none for the waters in which its own members dispute maritime boundaries.
That said, the southern flank was not absent from Ankara, being present in a different form. The most consequential southern flank business conducted at the summit was bilateral: Donald Trump, President of the US, signalled serious consideration of an F-35 Lightning II Joint Combat Aircraft sale to Turkey, although the transfer remains blocked by a legislative requirement that America certifies Turkey no longer possesses the Russian S-400 missile system. Additionally, both Greece and Israel have voiced objections, and can be expected to press them in the US Congress.
This mechanism deserves attention. A question bearing directly on the Aegean military balance was raised between Washington and Ankara, and the NATO states most immediately affected by it have no forum in which to be heard other than Congress. An alliance member lobbying American legislators against a weapons transfer to another NATO country is not evidence of a functioning southern flank architecture. It is evidence that no such architecture exists, and that in its absence the smaller Mediterranean allies are reduced to working through Washington rather than through NATO itself.
This is not to say that the southern flank is unimportant to NATO. Rather, it is handled bilaterally and transactionally, and remains unarticulated at the level of collective commitment. The 360-degree formula has been alliance language since 2016, and still carries very little operational content south of the Bosphorus.
Here is where the British position is genuinely distinctive. EU engagement with Ankara is constrained by the vetoes available to Greece and Cyprus as member states, and American engagement is bilateral and transactional by habit. The UK is bound by neither. It is a guarantor power under the 1960 Treaty of Guarantee, maintains functional relationships with Athens and Ankara simultaneously, and sits outside the institutional machinery that makes Turkish participation so difficult to arrange.
Convening across the Greek-Turkish divide is not a British aspiration as much as a British comparative advantage. No other ally holds the same combination, although when a drone struck RAF Akrotiri on 1st March 2026, France responded by deploying anti-drone systems to Cyprus and Greece – publicly committing to their defence. On 8th June 2026, France and Cyprus formalised this cooperation by signing a Status of Forces Agreement, establishing the legal framework for a French military presence on the island. France has built this framework from a standing start. The UK, which has held the Sovereign Base Areas and its presence in Akrotiri for decades, has yet to do equivalent strategic work with Cyprus, Greece, or Egypt, and from a far stronger institutional base.
The eastern Mediterranean is where NATO’s next decade will be tested. Ankara has confirmed that the test will not be met by declaration. Britain has the standing to shape it, and now has rather clearer evidence that no one else intends to do so.
Ethan Gallant is an open-source intelligence analyst working on sanctions networks, corporate ownership, and strategic infrastructure. He publishes methodology-led investigative casework at ethangallantosint.substack.com and is a member of Chatham House and RUSI.
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