How EU Enlargement Could Transform European Defence: Scenarios for a 2030 Agenda

To confront the resurgence of traditional geopolitics in Europe, the European Union (EU) should return to its oldest foreign policy tool—enlargement—to place defence transformation at the top of the agenda. As António Costa embarks on his tenure as president of the European Council (EUCO)—the organizational body tasked with setting political direction and priorities—starting in December, forming a consensus on enlargement will be at the forefront of his mind, and defence should underscore it.

Specifically, António Costa should work with the European Commission—the executive branch of the EU—to place a hard date of 2030 for the conclusion of accession talks for the EU’s 8th enlargement round, emphasising the incorporation of Turkey, Ukraine, and Georgia through differentiated integration to overcome internal and external political barriers. Differentiated integration allows EU member states to participate in specific areas of EU policy or legislation at varying levels, enabling them to opt in or out based on their preferences, capacities, or priorities, while maintaining overall membership in the Union. Focusing on the accession of these three countries can catalyse European defence capabilities and posture. Regardless of its success, the EU’s pursuit of this goal will yield positive results as it employs its most crucial foreign policy instrument to strengthen ties with these nations, which Russia and China are currently aggressively pursuing.

This analysis posits possible scenarios for the EU if it pursues this strategic objective, pointing to five different outcomes from least to most likely. While the differentiated integration accession of Turkey, Ukraine, and Georgia by 2030 (Scenario 1) is the least likely of the five, it would be the most beneficial for the EU.

EU accession of these three countries would bolster the EU’s troop capacity and posture in geographic pivot points vis-à-vis competitors and adversaries, integrate emerging defence technology, and expand access to natural resources that underpin the needs for an EU defence industrial base, all while opening processes for a reform to the Common Foreign and Security Policy (CFSP) through alterations such as qualified majority voting (QMV) in the Council, which would consolidate EU decision-making, enabling a more geopolitical EU.

The most probable outlook (Scenario 5) suggests that by 2030, Ukraine will be actively progressing on its path to EU accession, striving to meet the Copenhagen criteria (the essential conditions for EU accession as established by EUCO in 1993 requiring stability of democratic institutions, a functioning market economy, and the ability to take on EU obligations ), with full accession in the years to follow. Under this scenario, Turkey and Georgia would not achieve tangible accession or partnership gains, but pursuing the talks forthright would still likely draw the two countries closer to Brussels through undertaking internal reforms and facing increased pressure from their respective populations.

Under Scenario 4, an also very likely though less likely outcome than Scenario 5, in addition to Ukraine’s progress, Turkey and Georgia would be likely to secure special partnership statuses, granting them a role in the EU’s Common Security and Defence Policy (CSDP) and crisis management framework—with full EU membership unlikely in the near term.

There are numerous reasons for the increased likelihood of these scenarios, with the challenges carrying significant weight.

First, with the war in Ukraine ongoing and Russia planning a 25% defence spending increase by 2025, a protracted conflict appears likely. The longer the war persists, the more complex Ukraine’s EU accession will become.

Furthermore, Ukraine’s status as Europe’s largest agricultural producer may create tension among leading agricultural EU members like France, Spain, Italy, and the Netherlands. Following the war, these nations may resist a shift in EU funding allocations toward Ukraine. Additionally, with its population of 38 million, Ukraine’s accession would alter the EU’s power balance, potentially reshaping its representation in the European Parliament and increasing Ukraine’s influence in QMV.

However, integrating Ukraine within the CSDP should prove less challenging, given its modernized military, advanced equipment, and extensive combat experience in high-intensity warfare. Defence should be at the forefront of Ukraine’s EU accession.

Second, Turkey and Georgia’s pathway to special partnership status may encounter obstacles, particularly in Turkey’s case. Cyprus is expected to oppose closer EU-Turkey ties due to longstanding political and territorial disputes involving Northern Cyprus, which Turkey recognizes. Greece’s reaction remains uncertain, as it, too, has territorial and political disagreements with Turkey dating back to the 1960s. Nonetheless, a closer partnership with Turkey would undoubtedly strengthen the EU’s CSDP presence in the Mediterranean and Black Sea regions, enhancing strategic positioning in these critical areas.

Despite the challenges, pursuing an 8th enlargement round offers numerous incentives.

European Commission President Ursula von der Leyen proclaimed in 2019 that her Commission would be geopolitical, and post-full-scale Russian invasion of Ukraine, enlargement is the EU’s highest priority. As Hans Kundnani points out for Chatham House, “enlargement is the EU’s oldest foreign policy tool.”

As Laurence Boone, former French secretary of state for European affairs, and Nicu Popescu, former deputy prime minister of Moldova, outline for Euronews, the “usual process of technocratic integration” must commence with the traditional two pillars of enlargement—monitoring of European Community Laws and fundamental reforms of the rule of law and democratic standards—underpinned by the new third pillar of defence and security policies.

The EU today, with the possibility of a faltering U.S. in NATO, faces circumstances in which defence preparations must take a more forward innovative approach. Given these circumstances combined with internal infrastructure and governance challenges to EU strategic autonomy, the EU should abide by Catherine the Great’s quote, “I have no way to defend my borders but to extend them.”

What Enlargement Offers EU Defence

The EU has fallen behind near-peer adversaries in terms of military personnel, with some calling for conscription. Combining all member states’ active or reserve troops, the EU has 1.33 million military personnel, while Russia has 3.57 million, and China has a combined 4 million.

While conscription may be one solution, EU enlargement could be another. And given the European public is starkly opposed to conscription, enlargement should be the greater priority.

While European militaries may have superior logistics, professional forces, and defence technology, the war in Ukraine has demonstrated that wars today are still won in a numbers game—via soldiers deployed, money spent, and artillery supplied. Despite the EU collectively spending more on defence than Russia, these funds are fragmented, and Russia still has Europe beat on the other two neccesities for modern warfighting. Hence, the need for a defence-focused enlargement. 

The accession of Turkey, Georgia, and Ukraine would add a combined 2.97 million military personnel to the EU, bringing the EU’s total force capacity (without internal changes) to 4.3 million, a comparable number to near-peer adversaries. Turkey has 735,000 military personnel, Georgia has 37,000, and Ukraine has 2.2 million, many of which are battle-hardened.

Not only would these countries aid in achieving the necessary troop count to have resilience in context to adversaries, but shift the center of the EU east with geographic superiority in the Black Sea and an EU landbridge all the way from Bulgaria, through Turkey, and into Georgia in the Caucuses.

Individually, these countries also offer substantial benefits to the defence of the EU.

Ukraine now has one of the strongest armies in Europe and has learned how to withstand Russia in practice. In addition, Ukraine has been a laboratory for defence innovation both via their engineers and combat groups. Its special units have combined traditional NATO battle techniques with the use of various emerging technologies to innovate combat and hold an edge against Russia.

Ukraine is also a top-ten global supplier of critical resources and has the second-largest deposits of natural gas in Europe after Norway, necessary resources for supporting a continental defence industrial base.

Georgia has one of the most respected counterterrorism special forces units outside of NATO, which contributed greatly to the International Security Assistance Forces (ISAF) in Afghanistan in the early 2000s.

Turkey, while having one of the most fierce armies in Eurasia, is also at the forefront of emerging defence technologies that have been vital on the battlefield in Ukraine.

The Benefit of a 2030 Agenda

Enlargement focused on defence is a needed strategy from the EU to securitize Europe. Yet, political timing and urgency stands in the way of such an endeavour. Hence, European Council President Charles Michel advocating last year for EU enlargement by 2030. Michel did so recognizing that progress on both sides of the accession process will come with ambitious but realistic targets.

The benefit of a 2030 agenda pertaining to the accession of these three countries is threefold.

First, it manages expectations for enlargement, both internally and among candidate countries, allowing the involved parties to determine the necessary steps to accomplish this goal. The EU must transition from rhetoric to a concrete operational framework to advance this vision.

Establishing clear, actionable key performance indicators (KPIs) for Ukraine, Turkey, and Georgia will be essential to ensure measurable progress toward EU alignment. These KPIs should outline specific benchmarks, covering areas from governance reforms to defence integration. Equally critical is achieving a unified stance on these indicators across all EU member states. Only with a cohesive and consistent approach can the EU effectively support these countries on their respective paths while maintaining alignment with the Union’s broader strategic objectives.

Secondly, it has the potential to initiate CFSP reform through QMV, which would streamline decision-making and prevent a minority from undermining the majority’s EU geopolitical objectives.

Thirdly, expediting the processes for the countries’ inclusion would lessen China and Russia’s influence in the region. The lack of progress on enlargement has emboldened candidate countries like Turkey, Georgia, or the Western Balkans to seek partnerships elsewhere, signalling to China and Russia that their alignment is still up for grabs. 

To undertake such a deadline, the EU will have to reflect on its intended processes for enlargement. 

The EU’s ambiguity on enlargement reflects an unresolved internal debate: should EU enlargement be evaluated solely through the technical lens of the Copenhagen criteria, through strategic and geopolitical considerations, or by balancing both? Ultimately, enlargement is a political decision resting with the European Council, yet the Copenhagen criteria have often served as a pretext to delay discussions on enlargement—especially concerning the Western Balkans.

Choosing to balance both geopolitical consideration and the Copenhagen criteria would enable the EU to have a better posture in its neighborhoods by placing the ball in the court of candidate countries while overwhelming them with carrots—an approach that offers considerable appeal in contrast to competitive adversaries and one that has the support of the majority of these candidate countries populations.

Given these dynamics, the EU must engage in a strategic reevaluation of its enlargement process, setting a clear direction for how this process should unfold through the 2020s and beyond. A cohesive framework is essential to navigate the geopolitical landscape while maintaining the integrity of EU standards.

The Challenges

The EU faces significant challenges in its enlargement ambitions, particularly with the inclusion of Ukraine, Turkey, and Georgia. First, Ukraine’s ongoing conflict with Russia complicates its accession, as the prolonged war could delay Ukraine’s ability to meet EU standards. Furthermore, geopolitical tensions related to Turkey and Georgia’s special partnership status present hurdles, especially given long-standing disputes with Cyprus and Greece that could obstruct closer EU-Turkey ties, despite the strategic advantages for the EU’s CSDP in the Mediterranean and Black Sea.

Additionally, the EU is divided on whether enlargement should be based strictly on the Copenhagen criteria or should also consider strategic and geopolitical factors, an internal debate that complicates the path forward. To make enlargement by 2030 viable, the EU must develop clear, measurable KPIs for candidate countries, with consensus among all member states to ensure a consistent approach and avoid internal divisions.

Lastly, slow progress on enlargement has encouraged candidate countries like Turkey and the Western Balkans to explore partnerships with Russia and China, potentially undermining EU influence in the region. These challenges underscore the need for a unified EU strategy that balances technical and geopolitical considerations to effectively address European defence and security in an increasingly complex global landscape.

Scenarios

Assuming the EU takes these steps to announce the goal of an 8th enlargement by 2030 backed by a tangible strategy with a focus on defence integration of Ukraine, Turkey, and Georgia, these are some possible scenarios: