International Crisis Group - Briefing 99 / Europe 23 July 2026 20+ minutes - The EU and Türkiye: Uniting in Defence?

 International Crisis Group

Turkish President Recep Tayyip Erdogan meets with the President of the European Commission, Ursula von der Leyen, on the sidelines of the Summit of Heads of State and Government of NATO Member States in Vilnius, Lithuania on July 12, 2023. IMAGO / APAimages via Reuters Connect

Briefing  99 / Europe 23 July 2026 20+ minutes

The EU and Türkiye: Uniting in Defence?

As the post-World War II international order fades away, officials in Ankara and other European capitals are realising that great danger lies ahead if they do not work together on security. Threat perceptions differ, but they can still find pragmatic, flexible means of collaboration.

What’s new? War in Ukraine, questions about long-term U.S. commitments to Europe and European rearmament have pushed Türkiye and European Union member states toward closer security and defence cooperation. But differing strategic outlooks and longstanding sources of tension continue to tarnish the relationship.

Why does it matter? Türkiye is seeking to preserve its vital role in the Black Sea, diversify partnerships and limit dependencies at a time of growing geopolitical uncertainty. EU members want to bolster their deterrence of Russia and keep up support for Ukraine. Working together could help both meet their overlapping but distinct goals.

What should be done? Türkiye and other European governments, as well as the EU, should continue to pursue pragmatic, incremental defence cooperation through bilateral partnerships, flexible coalitions and, where possible, involvement in EU initiatives, while working to mitigate distrust and settle old disagreements. 

I.

Overview

Russia’s full-scale invasion of Ukraine and growing uncertainty about U.S. support have markedly shifted how Türkiye, other NATO members and European Union members that are not part of the alliance perceive their defence. Officials in both Ankara and the other capitals are realising that if they do not find a way to work together, they will face greater dangers in the future. All these states also broadly agree about the imperative of forging stronger deterrence and defence capabilities, countering Russian influence and supporting Ukraine. But in many other respects, their perspectives diverge significantly. Whereas many European states, particularly on NATO’s eastern flank, see Russia as a direct menace to their territorial integrity, Türkiye tends to view it more as a regional power whose influence must be managed. These differences, alongside distrust and political sticking points, are blocking stronger ties at a time when the two sides increasingly need each other.

As a NATO member since 1952, Ankara plays a central role in defining the alliance’s defence priorities. Türkiye maintains NATO’s second largest standing army – with more than 751,000 personnel, some half of whom are reservists – which has extensive combat experience. It hosts key NATO command structures. But its relations with the EU, of which it is not a member, are more complex. Türkiye’s stalled bid to join the bloc has left lingering tensions with several EU member states. This legacy, along with the EU’s limited scope for military industrial cooperation with non-members at a time when it is taking on increasing responsibilities in this area, is standing in the way of better defence relations. 

Questions remain as to how NATO’s evolving capabilities and the expansion of its defence industrial base will intersect with emerging European security arrangements.

Many of these issues came into sharper focus when leaders gathered in Ankara for the NATO summit in early July. The summit declaration reaffirmed allies’ commitment to collective defence, deterrence and the transatlantic bond, while also announcing more than $50 billion in new procurement and unveiling plans to expand arms manufacturing, including by eliminating trade barriers in the defence sector. But questions remain as to how NATO’s evolving capabilities and the expansion of its defence industrial base will intersect with emerging European security arrangements. Reflecting the thinking of many Turkish officials, President Recep Tayyip Erdoğan voiced concern about the limited role envisaged for non-EU NATO allies in European defence spending and procurement initiatives. 

Rather than seeking a single platform for cooperation in security and defence, other European states should pursue pragmatic, flexible ways to link up with Türkiye. They should rely less on EU channels, which tend to be clogged by political blockages, than on bilateral and mini-lateral arrangements that can circumvent these obstacles to respond quickly to exigencies. Support for Ukraine and efforts to forge a common approach to Black Sea security offer promising avenues for cooperation, as does deeper integration of Turkish and other European defence industries through production partnerships. When possible, the sides should seek to pair defence cooperation with related diplomatic initiatives. Such collaboration might not boost the EU accession hopes that linger in Ankara. But if successful, it could help build the confidence needed to address the differences that have long soured a relationship at the heart of European security. 

II.

The EU, Türkiye and Security in Flux

Perceptions of security threats differ in Ankara and other European capitals, but the shock generated by Russia’s all-out invasion of Ukraine has galvanised efforts to bolster Türkiye’s role in European security. 

After decades marked by competing views about how to handle Russia, there is now consensus among most of NATO’s EU members that Moscow poses a long-term threat to continental security. Eastern flank countries such as the Baltics and Poland had long warned Western European states of the risk of direct aggression from Russia, perceiving it to be an immediate, existential threat. They sought to build a security posture anchored in the credibility of NATO’s collective deterrence along its eastern borders and the capacity for rapid reinforcement and forward defence.1 Other European states – particularly in Western and Southern Europe – had tended to place greater emphasis on managing the risks of conflict with Russia while giving proper attention to other concerns, including instability in North Africa and the Middle East. 

Since 2022, however, the views of countries on Europe’s eastern flank have become dominant across Europe. As all-out war raged in Ukraine, EU member states and allied governments coordinated among themselves and with other backers to impose unprecedented sanctions on Moscow. Across the continent, governments have also hiked their defence spending, and several states have set about rearming their militaries and adjusting their force postures. The war has also reinforced Türkiye’s concerns about Russia, heightening its fears of further deterioration in the regional balance of power and prompting moves to strengthen Ukraine’s defence. But Ankara has been reluctant to pursue policies that, in its view, could make Moscow feel cornered and more likely to lash out, instead seeking to balance support for Ukraine with deterrence, efforts to contain rivalry with Moscow and preservation of regional stability.

A.

Differences and Common Ground between EU Countries and Türkiye

Kyiv’s European backers have embarked on a sweeping campaign of support for Ukraine’s economy and armed forces, disbursing close to €77 billion in direct military assistance. This aid has been channelled both bilaterally and through EU initiatives designed to reimburse member states for the supply of weapons, ammunition, air defence systems and tanks. EU member states’ contributions to Kyiv’s war effort have included Leopard tanks, fighter jets and a range of air defence systems.2 The share of support for Ukraine from backers in Europe and Canada has grown sharply since the U.S. ceased its own aid soon after U.S. President Donald Trump returned to office in 2025.3

Ankara, on the other hand, did not sign up to all these initiatives. It did not join the sanctions regime put in place by the EU, seeing participation as harmful to its economic interests and citing the lack of Turkish involvement in their design. But like most other NATO allies, Türkiye has supported Ukraine in its quest to defend itself from Russian aggression. Starting from before the full-scale invasion, Ankara has sold Bayraktar TB2 drones, heavy machine guns, laser-guided missiles, electronic warfare systems, armoured vehicles and protective gear to Kyiv.4 It continues to provide various forms of assistance, including to Ukraine’s border forces.5 Even so, Turkish aid is dwarfed by that from many EU member states.6 This assistance is also difficult to quantify because Ankara does not generally make public information about what it is donating as opposed to selling.

That said, Türkiye has made a major contribution to Ukraine’s defence. Turkish and Ukrainian officials alike frequently remark that comparisons based solely on the dollar value of military assistance understate Türkiye’s role, pointing to the early provision of weaponry that proved critical on the battlefield, Ankara’s role in facilitating endeavours such as the Black Sea Grain Initiative and prisoner exchanges, and the other sorts of cooperation mentioned above.7

Türkiye has also been an active participant in discussions with Ukraine’s other backers about preparing for the post-conflict period. Many such confidential conversations have taken place under the auspices of the “coalition of the willing” formed in early 2025, which gathers more than 30 EU and non-EU states.8 Designed to enable faster, more flexible coordination outside the constraints of formal institutions, the coalition has focused on supporting Ukraine’s position in negotiations and military planning for the war’s eventual aftermath. Reportedly, the possible post-war arrangements include a leading role for Türkiye in bolstering maritime security and freedom of navigation in the Black Sea. 

Ankara supports Ukraine because it shares with its allies the worry that a Moscow emboldened by victory would pose a major threat. In the past, Ankara’s desire to prevent a rupture with Moscow was a source of disagreement with some of its NATO allies. But today, in the face of increased speculation about a U.S.-Russia rapprochement, Ankara’s preference for hedging makes it more rather than less eager to seek common cause with other European capitals. 

In contrast to some of its allies, Ankara still does not appear to see the Kremlin as a near-term threat to Turkish territory or even to that of other NATO member states.

That said, in contrast to some of its allies, Ankara still does not appear to see the Kremlin as a near-term threat to Turkish territory or even to that of other NATO member states. Instead, Turkish policymakers tend to fear that such a direct confrontation is more likely to arise if Moscow were to feel trapped, with few options but to fight.9 Nonetheless, they do not want Russia’s battlefield gains in Ukraine to extend further along the Black Sea coast, which might weaken Türkiye strategically. 

In Ankara’s corridors of power, the most common stance toward European efforts to deter Russia is caution. Not only do many Turkish officials doubt that sanctions and the like will work, but they also worry that these policies could backfire, particularly if Ankara were seen to be joining allies in a comprehensive bid to isolate or thwart Russia. In that event, they fear, Moscow might retaliate against Türkiye in other theatres, such as the Caucasus, or through economic and hybrid moves, while also stoking tensions with other NATO members.10 This strategic calculation, combined with a long history of simultaneously competing, coordinating and trading with Moscow, has nudged Ankara toward combining support for Ukraine with efforts to preserve channels with Russia and play a role in seeking a diplomatic solution to the war. 

B.

The Black Sea

Türkiye’s involvement in preparing a set-up for Black Sea security in the aftermath of war reflects its important role in the region. With the sea’s longest shoreline, Türkiye is already a linchpin of NATO activity in the area: since 2024, it has worked with Romania and Bulgaria in a new Black Sea task group aimed at curbing the danger of mines.11 Turkish officials argue that Ankara provides a large share of the information NATO requires to assess risks in these waters.12 It is hard to imagine a future in which Ankara is not at the centre of Black Sea military planning. But Ankara’s interests, while broadly aligned with those of its European partners, are not identical to them. 

The EU’s Black Sea Strategy, published in May 2025, highlights the need to counter Russian military and non-military activity; protect critical infrastructure, energy supplies and trade routes; and ensure maritime security. In the words of EU officials and member state diplomats, the document reflects widening recognition of the Black Sea region’s strategic importance after the Russian offensive in Ukraine exposed Europe’s vulnerability on its eastern flank. It also signals the EU’s wish for a wider footprint in a region where most littoral states are either members of the bloc or candidate countries.13 Plans are afoot for Romania and Bulgaria to jointly host the EU Black Sea Maritime Security Hub in Constanta and Varna, which would serve as a coordination centre for monitoring non-military threats and protecting critical undersea infrastructure.14

Most EU member states agree that Türkiye will have a critical role to play in the future hub’s operations. Ankara, however, is concerned that the planned centre could duplicate existing NATO functions and that Türkiye, a Black Sea country that is not in the EU, could wind up on the outside looking in. 

NATO has also bolstered its infrastructure in both Romania and Bulgaria as part of its shift since 2022 toward reinforcing deterrence along its eastern flank. While Türkiye supports strengthening the defence of Romania and Bulgaria, it is also wary of a larger NATO military presence in the sea itself, fearing it could provoke Russia, increase escalation risk and undermine the regional balance of power.

Türkiye shares the desire to prevent Russian dominance in and around the Black Sea. But while the EU increasingly sees the region as a contested space where it must strengthen its hand and counter Moscow’s ability to project power, Ankara’s priority is to maintain regional stability, while protecting its own standing and naval strength. Ankara wants to deter Russia and stop it from acquiring more territory along Ukraine’s coast – but it also wants to avoid confrontation. It is therefore cautious about initiatives that could enhance Romania’s role, concerned that these might erode Türkiye’s own position at the heart of Black Sea security matters and risk angering Russia. Some Turkish officials, in fact, suspect that certain allies may want to weaken Ankara’s regional influence rather than support it. 

In Ankara’s view, Black Sea security is grounded in the 1936 Montreux Convention, which gives Türkiye authority to regulate naval passage through the Bosphorus and the Dardanelles (known together as the Turkish Straits) and restricts the tonnage and duration of stay for warships belonging to non-littoral countries in the Black Sea. Turkish officials emphasise what they term the principle of regional ownership: that Black Sea security arrangements should be led primarily by its coastal states, not other powers. Throughout the full-scale war in Ukraine, Ankara has strictly enforced Montreux’s wartime provisions, preventing Moscow from reinforcing its naval presence with ships from other ports. While no NATO member is taking part in the war directly, Ankara believes that by precluding other countries’ warships from entering these waters it has helped stave off the risk of escalation. 

[The] differences in approach to the Black Sea underline how Türkiye now occupies a pivotal but ambivalent position in the European security order.

These differences in approach to the Black Sea underline how Türkiye now occupies a pivotal but ambivalent position in the European security order. NATO remains central to deterrence on the eastern flank, particularly for the states most exposed to Russia. The EU is expanding its role in defence coordination and regional initiatives such as those in the Black Sea, though its influence remains uneven and under construction. Türkiye, for its part, is firmly embedded in NATO’s security architecture. Though it remains guided by its own regional priorities, above all in the Black Sea, both Türkiye and other NATO members regard existing alliances as a major asset and agree that the defence industry is in urgent need of a boost. 

Because it is not a member, but instead a decades-long candidate country, Türkiye has a more troubled relationship with the EU, and Ankara does not set its priorities to match those set in Brussels. The consequence is a pattern of partial alignment with the EU – cooperation where interests converge, but a degree of divergence over how security in the region should be organised.

III.

A Role for Türkiye in EU Defence

Among the issues Türkiye and other EU and NATO European governments agree on is the need to boost their defence capabilities, including industrial production, and to reduce dependence on the U.S. As NATO’s second largest military power, and boasting a large defence industry, Türkiye has become increasingly prominent in European discussions about achieving strategic autonomy, with some of the states that were previously reticent about a larger Turkish role in European security now more amenable to cooperation. Ankara, in turn, is eager to be part of its allies’ long-term rearmament plans. That said, Ankara differs with several other European capitals regarding how to go about building up a defence industrial base. 

A.

The Case for Greater Defence Sector Cooperation

Many European NATO allies are interested in closer defence sector cooperation with Türkiye, mainly due to uncertainty about U.S. commitments to Europe. The U.S. had been at the vanguard of European defence after World War II, with allies repaying Washington with support on myriad foreign policy issues. But if generations of U.S. and European leaders questioned the bargain, none have done as much to shatter it as President Trump. Having disparaged NATO in his first term, he has pledged in his second to make large troop withdrawals from the continent and aspired to annex the autonomous Danish territory of Greenland.15 Even Europeans who had long favoured more military and diplomatic independence have found Trump’s attitude shocking.16 They had envisaged that the shift to greater local leadership and a stronger military would be gradual, whereas the White House has indicated that the U.S. might simply pack up and leave at short notice.

For now, U.S. forces retain a substantial presence in Europe, and Washington continues to provide NATO with strategic leadership, the alliance’s largest army and its most advanced capabilities. But few in Europe think this set-up will be permanent. European NATO members have come to believe that the best option is to keep the U.S. engaged for as long as possible, while developing their own firepower and finding new partners as rapidly as they can.17

Türkiye ... appears to be a natural partner in re-equipping Europe to face potential threats ahead.

Türkiye, meanwhile, appears to be a natural partner in re-equipping Europe to face potential threats ahead. While many European states scaled back defence spending after the end of the Cold War, Türkiye has invested heavily in its defence industry for decades, especially since 2004, with the goal of reducing its dependence on allies while tackling security concerns at home and abroad. In 2004, the Secretariat of the Defence Industries began offering large tenders to private firms, aiming to boost domestic production to meet the requirements deriving from Ankara’s conflict with the Kurdistan Workers Party or PKK – a group that Türkiye, the EU and the U.S. all formally designate as a terrorist organisation.

Though Türkiye has long cooperated with NATO allies in defence production and procurement, its integration into Europe’s broader defence industry has so far remained limited. Ankara’s military manufacturing does not always offer like-for-like replacements for U.S. weaponry. But the Turkish defence industry could still be well positioned to work with others to define and meet emerging needs. Manufacturers in the country, like their counterparts around the world, are rethinking how to shift from peacetime production, with its long lead times and high costs, to faster, cheaper approaches, particularly in making drones for various strike, reconnaissance, lift and other missions. Besides drone production, Türkiye’s missile manufacturing and its flexible assembly lines offer a range of near- and longer-term synergies with other European military industries.18

Ankara has reasons of its own to seek closer defence cooperation with its allies and other European states. Besides viewing cooperation as a lever for boosting Türkiye’s defence sector through new opportunities for financing, technology transfer and industrial partnership, Ankara also sees it as a way to revive broader political and economic engagement with the EU. Turkish policymakers hope security collaboration with EU members, especially given the growing EU role in defence industrial matters, could help unlock progress on modernisation of the EU-Türkiye Customs Union and other economic integration plans.

B.

Opportunities for Defence Collaboration with the EU and Its Member States

While defence ministries field armies and NATO coordinates military planning, the EU has now taken on the job of helping pay for rearmament. The bloc has launched a series of initiatives to reinforce the defence industry and encourage joint procurement. Building on other initiatives such as the European Defence Fund (EDF), designed to fund joint defence research, the European Commission in March 2025 published its White Paper for European Defence, identifying critical shortfalls in areas such as drone capabilities, air and missile defence, electronic warfare and artillery systems.19 In May 2025, the European Council adopted the Readiness Europe Plan, including a €150 billion loan package known as Security Action for Europe (SAFE), designed to finance purchases from EU producers, boost collaborative procurement and allow the participation of third countries, such as Türkiye, the UK, Norway and Ukraine. SAFE reflects the EU’s recognition that these countries may be critical to production at a time when member states face shortfalls in their pools of skilled labour, as well as bottlenecks in supply chains and manufacturing throughput. 

In several of the areas flagged in the White Paper – particularly drones, armoured platforms and certain air defence components – Türkiye already has production lines that can be scaled up, systems that are interoperable with those of NATO and fast delivery cycles. With more than 3,000 defence firms and a track record of cost-effective output, Türkiye could arguably turn European funding into deployable military assets more rapidly than EU member states could by themselves, using their own production sites.20

That said, most of the EU’s defence financing initiatives, such as the EDF and SAFE, are designed primarily to boost collaboration among member states, allowing for third-country participation only under specific conditions. Under SAFE, participation by non-EU members is capped – generally at 35 per cent per project – and is often limited to subcontracted roles. Project leadership and preferential financing terms, such as long-term low-cost loans, are largely reserved for EU members. These restrictions apply to others besides Türkiye: negotiations over the UK’s participation in SAFE collapsed in late 2025 when London sought better terms and participation beyond the 35 per cent cap.21

Reservations about closer defence cooperation with Türkiye are not confined to Greece and the Republic of Cyprus.

In addition to constraints on non-EU members, Türkiye must overcome political opposition from within the bloc. In their efforts to restrict Turkish involvement in EU defence initiatives (discussed in Section III.A below), Greece and the Republic of Cyprus have linked potential participation to resolving the Cyprus issue as well as disputes in the Aegean and eastern Mediterranean, while continuing to argue that Ankara is not adequately aligned with EU foreign policy positions.22 Reservations about closer defence cooperation with Türkiye are not confined to Greece and the Republic of Cyprus. Concerns have also been expressed elsewhere in the EU about Ankara’s geopolitical orientation and its implications for European security. 

Türkiye, for its part, is also pursuing bilateral defence cooperation with several EU member states. Ankara has signed bilateral or industrial partnerships with Italy, Spain, Germany, Poland and Romania.23 These include armoured vehicle exports to Romania, drone sales to Poland and Romania, cooperation on maintenance for military aircraft and equipment, and a strategic partnership with Italy to develop in tandem advanced drone technologies. Notably, Türkiye is participating in the German-led European Sky Shield Initiative (ESSI) – a plan to create an integrated missile defence system in Europe. Ankara, whose air defence industry has grown rapidly in recent years and is developing the Steel Dome system, could play a growing role in Europe’s future air and missile defence, even if cooperation is developing from a low base and its ability to support Ukraine’s current air defence remains limited.24

Even so, France and other states have expressed concern about reliance on non-EU systems within ESSI, preferring a greater emphasis on technologies produced within the bloc.25 Their qualms reflect a broader debate among EU members: whether states should rearm by building a tightly integrated “buy European” industrial base or whether urgent needs make cooperation with third countries essential. In any event, the decision may not be entirely in EU members’ hands. Some capabilities require partnership. Defence sector cooperation with Ukraine, for instance, has transformed from projects intended solely to assist Kyiv into a comprehensive effort involving the transfer of Ukrainian know-how and capabilities to NATO member states. As Ukrainian President Volodymyr Zelenskyy has pointed out, Ukraine and Türkiye’s combined military strength could rival Russia’s.26

IV.

Barriers to Greater Cooperation

Despite shared economic and security interests, EU-Türkiye relations in the 21st century have suffered from distrust, bilateral disputes, diverging strategic priorities and conflicting views about Türkiye’s place in Europe. While some EU member states have remained supportive of closer ties with Ankara over the last quarter-century, others have grown more sceptical. The result is that efforts to cooperate more, whether in security or economic affairs, have been fraught. 

A.

The Causes of Discord

Türkiye has been an EU candidate country since 1999 and opened accession talks in 2005. But progress toward membership was soon stymied. The official EU line is that blame lies primarily with the Turkish government’s moves to consolidate power and constrain civil liberties, which EU officials have described as incompatible with EU standards on the rule of law (the so-called Copenhagen criteria that guide the accession process).27 As an EU official told Crisis Group: “Türkiye needs to understand that EU enlargement is a normative process. If you want to be part of the club, you have to play by its rules. One cannot join the club on one’s own terms”.28

For some member states, however, democratic backsliding was not the only thing precluding Turkish membership. Even in the 2000s, before Ankara’s later repressive policies took hold, voices in centre-right and conservative circles across the bloc described the EU as a project rooted in the continent’s “Judeo-Christian” heritage.29 Others emphasised the importance of secularism, shared history and common milestones in political development. Over time, political changes under Turkish President Recep Tayyip Erdoğan, including what parts of Europe viewed as a stronger role for religion in public life, reinforced doubts among critics in the EU about Türkiye’s suitability as a candidate for membership.

Some EU and member state officials have been openly sceptical as to whether Türkiye, with its predominantly Muslim population, could fit into the bloc.

Even without those changes, some EU and member state officials have been openly sceptical as to whether Türkiye, with its predominantly Muslim population, could fit into the bloc. France’s former President Nicolas Sarkozy repeatedly argued that Türkiye did not belong in the EU, proposing instead a “privileged partnership”.30 Germany’s former Chancellor Angela Merkel also voiced concerns, such as for the EU’s identity, its political cohesion, the limits of its borders and its ability to integrate new members.31 As the Turkish government continued to tighten its grip on power, crackdown on dissent, civil society and the media and weaken judicial independence, especially after the failed coup attempt in 2016, accession talks lost all momentum. By 2018, they were in effect frozen.

Relations between Türkiye and two EU member states, the Republic of Cyprus and Greece, also played an important role in estranging the country from the bloc. 

The Republic of Cyprus, which joined the EU in 2004 and is the internationally recognised government of the island, has no diplomatic relations with Türkiye. Ankara recognises only the “Turkish Republic of Northern Cyprus”, a self-declared state recognised by no other country. The Republic did not block accession negotiations with Türkiye in 2005, hoping to encourage normalisation of relations. But Ankara’s non-recognition of the Republic of Cyprus, its military presence in the island’s north – which UN Security Council resolutions refer to as the occupied part of the Republic – and its support for the self-declared “Turkish Republic of Northern Cyprus” became major obstacles to Türkiye’s accession process. These issues lie underneath the Republic’s security concerns today.32

In 2006, the EU froze eight negotiation chapters when Türkiye refused to open its ports and airports to the Republic of Cyprus under the Ankara Protocol, which extended the EU-Türkiye Customs Union to the ten states that had joined the EU in 2004, including the Republic.33 The bloc also decided that no negotiation chapter could be concluded until Türkiye had fulfilled these obligations.34

Greece backs the Republic of Cyprus in its position regarding the dispute between Greek Cypriots and Turkish Cypriots.35 It also has longstanding disagreements with Ankara over maritime claims and other issues in the Aegean, many of which predate Türkiye’s accession process by decades. While Athens supports Türkiye’s accession in principle, it has consistently argued that progress should be linked to normalisation of relations with the Republic of Cyprus and efforts to reduce tensions with Greece. In this connection, Greek officials say Ankara should refrain from claims and actions that Athens considers contrary to international law.36

[Both Greece and the Republic of Cyprus] have opposed recommendations that EU-Türkiye high-level dialogues, suspended since 2019, resume.

Today, both Greece and the Republic of Cyprus argue that Türkiye should not benefit from EU funds or participate in security initiatives while it is disputing an EU member state’s sovereignty.37 Greece also views a 1995 Turkish parliamentary resolution stating that any Greek extension of territorial waters from six to twelve nautical miles should be treated as an act of war as inconsistent with international law.38 As a result, both countries have opposed recommendations that EU-Türkiye high-level dialogues, suspended since 2019, resume. They have resisted proposals to update the EU-Türkiye Customs Union outlined in an official report from 2023.39 Furthermore, they have refused to accept Turkish involvement in EU defence initiatives, pointing to provisions that allow member states to object to the participation of third countries on national security grounds. They argue that Turkish participation in these efforts is detrimental to their national security interests.40

From Ankara’s perspective, the accession of the Republic of Cyprus two decades ago has in effect held the EU-Türkiye relationship hostage to the island’s internal divisions. Officials from EU institutions and member states, however, argue that Türkiye needs to recognise political realities, including the views of all the EU’s members, and try to establish support among all of them if it wants to tighten its links with the bloc.41

B.

Foreign Policy Differences

Greece and the Republic of Cyprus are not the only impediments to stronger ties between Türkiye and the EU. If there is one issue on which most EU member states agree, it is that differences with Türkiye on key foreign policy issues represent a major obstacle to cooperation on various fronts. As several member state diplomats told Crisis Group, Türkiye aligns with only 4 per cent of EU declarations – far below any other candidate country, including Serbia, which stands at 63 per cent.42

Turkish officials insists that this measure is not a fair reflection of alignment with the EU on matters of foreign policy, since Ankara is often not notified of these declarations in a timely way, let alone invited to share information or ideas that could enrich the discussions leading up to each decision.43

Differences between the two, however, are hard to disguise. EU and member state officials point to Ankara’s decision to purchase Russian S-400 air defence systems in the period 2017-2019, which its NATO allies saw as incompatible with the alliance’s weaponry and a security risk.44 Migration control is also a sensitive issue. While many European governments view cooperation with Ankara as critical to reducing undocumented arrivals, some officials worry that Türkiye has used its role in managing migrant flows to extract political and economic concessions from the EU.45 Support for Azerbaijan in its 2020 offensive to retake Nagorno-Karabakh from Armenian control provided yet another example of Türkiye’s disagreements with a number of European governments. 

The full-scale Russo-Ukrainian war ... has alarmed Türkiye and the EU in equal measure, but led to subtly different responses from each of them.

These distinct foreign policy outlooks have surfaced once again during the full-scale Russo-Ukrainian war, which has alarmed Türkiye and the EU in equal measure, but led to subtly different responses from each of them. First, Ankara did not sign up to EU sanctions against Russia, and it has maintained economic, energy and diplomatic ties with the Kremlin even while supporting Ukraine (see Section II.A).46 Ankara also imposed conditions on Sweden’s NATO accession, which slowed both its membership path and Finland’s. 

For several European states, these moves indicated important divergences between themselves and Türkiye. They believed that the Turkish government saw the threat from Russia and a unified NATO response as secondary to its other interests. They also suspected that Ankara was willing to take advantage of its allies’ security concerns to secure benefits in other areas, such as tougher action against individuals and organisations it associated with the PKK (and the Gülen movement, which the Turkish state calls the Fethullahist Terrorist Organisation and holds responsible for orchestrating the 2016 coup attempt), lifting defence export restrictions imposed after Türkiye’s 2019 Syria incursion, and greater responsiveness to Turkish extradition requests.47

While the views of many European governments are now gradually shifting in favour of greater cooperation with Ankara, EU member states continue to disagree about how far it should go. Germany, for example, backs closer ties.48 During negotiations over a text intended to spur a reboot of EU-Türkiye relations, Germany and the Netherlands pushed for a greater focus on mutually beneficial changes in areas such as trade, migration, visas and dialogue. But the positions of Greece and the Republic of Cyprus remain unchanged, and a number of states continue to raise Türkiye’s human rights record as a major hindrance to collaboration with the EU. 

Paris, meanwhile, wants pragmatic cooperation, but with limits and safeguards. While it sees engagement with Türkiye as important to its goal of achieving greater European strategic autonomy and reducing reliance on the U.S., it remains wary of trading dependence on Washington for greater reliance on the defence industry of another non-EU power. Several French officials have additional reasons for caution, rooted in their criticisms of President Erdoğan’s policies and their view of Türkiye as a geopolitical competitor in Libya, Africa, the eastern Mediterranean and the South Caucasus.49

C.

The View from Türkiye

Ankara, recognising that Türkiye’s long-term security is twinned with Europe’s as a whole, would prefer to be embedded in a durable pan-European defence arrangement. At the same time, Turkish officials are uncertain whether emerging European plans for regional security will adequately reflect Türkiye’s interests or provide reliable guarantees of protection from threats it may face. As a result, Ankara is hedging, trying to remain engaged within evolving European set-ups, like the aforementioned “coalition of the willing”, while avoiding overdependence on any format that might not prove effective and from which it might eventually be excluded. 

Ankara harbours profound doubts about the intentions of continental Europe. Many Turkish officials believe that most European states are prepared to reach out to Türkiye when doing so serves their immediate strategic needs, but that they are less likely to extend meaningful support when Türkiye’s own security is at stake. 

This perception is shaped to a large extent by Ankara’s frustrating EU accession process. Steeped in the history of that failure, many Turkish officials view the EU and its member states as intent on excluding Türkiye from their closed circle. These officials, and much of the Turkish public, are convinced that accession was halted not because of high-minded EU principles, but because of prejudice. 

Turkish officials hold that the push for reform triggered by the EU acceptance of Türkiye’s candidacy in 1999 could have been sustained had the accession process remained credible. In their view, however, the EU’s decision to admit the Republic of Cyprus in 2004, despite Greek Cypriots’ rejection of the Annan Plan for reunifying the island, was a decisive blow.50 Combined with hostile or anti-Muslim and anti-Turkish sentiment in several other EU member states, domestic political calculations in these same countries, and economic anxieties about integrating a country as large as Türkiye, the obstacles on the road to membership soon became insurmountable.51

Today, Turkish officials argue that if the EU wants to be a diplomatic heavyweight, it should not let the Republic of Cyprus play such a prominent part in preventing cooperation.52 But Ankara also has reason to fear that anti-Turkish discrimination persists in Europe’s policy-making elites. As recently as April, European Commission President Ursula von der Leyen, when referring to EU enlargement, remarked that Europe must “complete the European continent so that it does not fall under Russian, Turkish or Chinese influence”.53 Bracketing Türkiye alongside Russia and China was seen in Ankara as further evidence that the EU remains ill-disposed toward the country.54

Ankara has been deeply frustrated with continuing support from key European states for pro-Kurdish political networks, which Türkiye views as associated with the PKK.

A variety of other gripes have also helped sour the relationship. Ankara has been deeply frustrated with continuing support from key European states for pro-Kurdish political networks, which Türkiye views as associated with the PKK. As noted above (see Section IV.B), the issue rose in prominence during Sweden’s NATO accession process. Turkish officials argued that Stockholm had become overly permissive toward PKK-linked activism, fundraising and political mobilisation, leading it to link its approval of accession to a change in the Swedish stance. 

The failed coup attempt of July 2016 also remains a sore point. Across Türkiye’s political spectrum, many have decried responses from EU members to the coup attempt as slow, muted or overly cautious. In Ankara’s view, most European countries, including vocal proponents of the rule of law and democracy, hesitated to show solidarity with Türkiye’s elected government at a moment when its state institutions were under attack and hundreds of civilians were killed.55

Ankara, meanwhile, remains sceptical that the EU is willing to come to Türkiye’s defence following experiences involving member states of the bloc that are also NATO allies. In 2015, as the civil war in Syria intensified, the U.S. and Germany withdrew their NATO-assigned Patriot air defence batteries from Türkiye, citing operational and modernisation requirements. While Spain continued the Patriot mission, keeping NATO involved in Türkiye’s air defences, Ankara viewed the reduction in coverage as a sign that allies were unwilling to keep up support at a time of heightened regional instability.56 Similarly, when Russia imposed sanctions on Turkish agricultural exports following Türkiye’s downing of a Russian jet in 2015, Ankara received neither meaningful economic backing nor strong political support from its European allies. Episodes such as these have helped shape Ankara’s reluctance to cut ties with Moscow, despite their frequent disagreements. 

Ankara’s frustration with allies’ lukewarm and divided response to Russia’s 2014 occupation of Crimea was also pronounced. Türkiye saw the move not only as a blow to Ukraine’s sovereignty and territorial integrity, but also as an immediate danger to the peninsula’s indigenous Crimean Tatar population and a major threat to stability (and Turkish power relative to Russia) in the Black Sea region.57 At the time, Erdoğan called upon “the West” to speak out more strongly against the invasion of Crimea.58 The expectation since February 2022 that Türkiye should fully align with other European countries’ now far more forceful Russia policy has especially rankled those who believed Ankara’s concerns were shunted aside in 2014.59

As for the Turkish approach to sanctions on Russia, officials point out that it is in line with Ankara’s history of abiding only by UN-imposed restrictions, not by unilateral measures adopted by individual countries or coalitions.60 They go on to note (as do many others) that because Ankara was not consulted about the sanctions’ design, it was unable to negotiate carveouts like the ones EU member states put in place for themselves.61 Turkish officials also question whether the EU can maintain the unity it has shown in recent years regarding Russia and other matters. In their assessment, the bloc’s internal political cleavages, its consensus-based decision-making and the limits on its hard power will continue to constrain its ability to act swiftly and decisively.62

Notwithstanding [the] long list of ... grievances with the EU, Turkish officials have a variety of views about how much cooperation with the EU is desirable in the future.

Notwithstanding this long list of keenly felt grievances with the EU, Turkish officials have a variety of views about how much cooperation with the EU is desirable in the future. Foreign Minister Hakan Fidan, much of the diplomatic establishment and various senior figures in the president’s office tend to understand defence cooperation with Europe in pragmatic terms. They wish to harness cooperation to benefit the Turkish defence industry, as well as to reinvigorate EU accession talks, modernise the customs union and advance a more liberal regime of visas for travel between Türkiye and EU member states. But nationalist elements within the ruling alliance are sceptical. Their views on Cyprus and Aegean rights are more hawkish, reflecting suspicion that the EU is using its prerogatives to check Türkiye’s strategic autonomy and regional influence.63

Scepticism about the EU cuts across party lines and is not limited to the ruling alliance. Even the main opposition party, the Republican Peoples Party, remains ambivalent about deeper security cooperation with the EU. While much of the opposition criticises democratic backsliding in Türkiye and supports stronger ties to continental powers, most also worry that other European states do not respect Türkiye’s security or strategic interests. They also wonder if democracy and rule-of-law concerns, real as they are, are being used primarily to justify policies intended to corral Ankara and contain its regional sway.64 Many in the opposition are particularly critical of the government for cooperating with the EU on migration, arguing that it has turned Türkiye into a permanent holding pen for refugees.65

The result is public ambivalence: many Turks continue to associate mainland Europe with economic opportunity, rule of law and institutional stability. Simultaneously, they doubt that fellow European states intend to bring Türkiye into the bloc or support Turkish interests under any circumstances. 

V.

The Way Forward

Whatever anyone’s preferences and hopes, the future of European security is likely to emerge from a patchwork of overlapping initiatives that are crafted to meet urgent needs. The same is true of Europe’s defence-industrial base. Furthermore, EU governments, non-EU NATO allies and Ukraine recognise that in many cases existing institutions, including NATO and the EU, cannot act at the speed required by fast-changing threats, even as U.S. interest in propping up the region’s security wanes. New, more flexible approaches, whether coalitions of the willing, mini-lateral defence initiatives or bilateral cooperation at various levels aim to do what the more traditional institutions on their own cannot. These countries are likely to continue cooperating through both these new formats and established bodies. 

As for the defence industry, cooperation – at least in the near term – is likely to depend less on EU instruments such as SAFE, which are exposed to the political headwinds from troubled EU-Türkiye relations, and more on bilateral co-production partnerships involving public and private defence firms.

For example, Baykar’s joint venture with Italy’s Leonardo, formalised in mid-2025, brings Turkish expertise in designing and building uncrewed systems to a major European company whose production lines remain inside the EU. Similar arrangements, which can also include provision of components by Türkiye for products manufactured in EU member states, will enable rapid scale-ups of output and give Turkish companies access to technology, financing and European markets. 

Support for Ukraine offers ... [an] avenue for defence-industrial co-operation.

Support for Ukraine offers another avenue for defence-industrial cooperation. The cessation of U.S. assistance to Kyiv has led European NATO members to step up their own production as well as to introduce the Prioritised Ukraine Requirements List, an alliance-coordinated initiative to support the purchase of U.S. weapons systems for Ukraine, bolstered by the EU’s €90 billion loan to Kyiv.66 Ukraine is in perennial need of more layered air defences to handle Russian missile and drone barrages, stronger resilience in the face of electronic warfare, and long-range strike capabilities to hit logistics and command nodes in Russia, including with drones. Scaling up drone and ammunition production for Ukraine and beyond will require investment in industrial capacity, there and elsewhere.67 Türkiye can contribute in several, albeit not all, of these areas (for now, it has little to offer when it comes to layered air defence and long-range capabilities, though it may have more in time). 

Turkish assistance to Ukraine will not look exactly like that of other supporters. But so long as it is complementary and coordinated, it will be welcomed. Kyiv has been a recipient of Turkish military aid since 2019 while remaining aware of (if not always happy with) Ankara’s constraints, including its desire to avoid confrontation with Moscow. It is unlikely that Ankara will make large donations of military equipment to Kyiv or advertise the help it is giving. But it can continue to provide intelligence and invest in co-production initiatives that will strengthen Ukraine’s arms industry over the long term. Given its niche industrial capabilities and faster production cycles, Türkiye could feed into European support packages for Ukraine.

Recognition of the security benefits of improved cooperation with Ankara has led to policy shifts across the EU. Most recently, during negotiations on the EU’s April 2024 Council Conclusions, an official statement that sets the political direction agreed upon by the 27 member states, Germany and the Netherlands sought to prevent the Greek Cypriots from blocking deeper engagement with Türkiye, pressing the Republic of Cyprus to soften their objections and adopt more balanced language regarding the country.68

Ankara is concerned that even if it stays outside the formal EU framework, it could still be sidelined once the immediate imperatives of the Ukraine war fade away.

A greater Turkish role in European defence appears to be winning over many European states to the prospect of a stronger relationship with Ankara. But after decades marked by slow-burning resentment, dangers and pitfalls remain. Ankara is concerned that even if it stays outside the formal EU framework, it could still be sidelined once the immediate imperatives of the Ukraine war fade away. Furthermore, any EU efforts to duplicate or replace NATO (and Turkish) capabilities and roles in the Black Sea will be seen in Ankara as a bid to push Türkiye aside. EU members, meanwhile, are driven by the imperatives of fostering greater strategic autonomy and ensuring their long-term security. While diversifying partnerships is one component of this project, another is avoiding dependence on partners that are not fully aligned with their interests. 

Rooting greater cooperation solely in ad hoc defence and security co-operation might be fruitful in the short term, but it has its risks. It could create a narrow, transactional relationship that remains vulnerable to political disputes and ends up confirming Turkish fears about the EU’s trustworthiness. Stronger cooperation would ideally mean establishing bonds beyond the defence industry and military planning to encompass broader strategic and diplomatic questions shaping European security. The two sides should make more regular efforts to narrow differences in threat perception and help identify areas of shared interest. June’s flurry of visits by senior EU officials to Ankara could be the foundation for a sustained high-level dialogue on European security, allowing the sides to exchange assessments of evolving threats and to coordinate more closely where their interests converge.69

Ankara is already involved in discussions of the post-war European security order, post-ceasefire arrangements in Ukraine, the future of the Black Sea and Ukraine’s reconstruction, because these projects are critical to Turkish interests and will require Turkish participation. Turkish authorities will continue to be a crucial voice regarding the Black Sea given that, under the terms of the Montreux Convention, they will decide when normal passage through the Turkish Straits resumes. Ankara’s channels with Moscow may likewise prove invaluable over the long haul to silence the guns in Ukraine. Should the two sides look further than ties in the defence and arms industries, there is much they could do to forge a stronger, more stable relationship to the benefit of the region as a whole.

VI.

Conclusion

The geopolitical logic driving closer cooperation between Türkiye and most other European states is compelling. While Türkiye and its European partners continue to differ on many issues, they face the same long-term conundrum: the U.S. is less vested in their security than in the past, and instability emanating from Russia is unlikely to disappear even if the fighting in Ukraine subsides. Their shared interest in strengthening deterrence, preserving Black Sea stability and supporting Ukraine begs for closer diplomatic and defence coordination, even if their political disagreements continue to grate.

While staying mindful of the differences that have estranged them and the political hurdles in the path of stronger relations, EU member states and Türkiye should continue to pursue pragmatic and flexible forms of cooperation on behalf of their shared security interests. These are likely to feature at the forefront of bilateral and mini-lateral arrangements that can circumvent the constraints on working through conventional EU institutional channels, where the blockages to partnership tend to be most stubborn. In the defence sphere, this cooperation could include expanded industrial links, as well as more regular involvement of Türkiye in ad hoc European defence and diplomatic initiatives. The partnership should extend to greater coordination in supporting Ukraine and making post-ceasefire arrangements, as well as to closer consultation on Black Sea, and broader European, security. 

These steps may fall short of resolving deeper disagreements or reviving Türkiye’s EU accession bid. But they could gradually rebuild trust and prevent the broader relationship from being held captive by bilateral quarrels that are unlikely to be resolved anytime soon.

Istanbul/Brussels, 23 July 2026