NATO without Consensus: How Ukraine Is Forcing the Alliance to Rethink Itself
The war in Ukraine has become a revolutionary catalyst for NATO's very existence. Russia's confrontation after 2022 forced the Alliance to address long-taboo questions: how suitable is the system of unanimous decision-making in the context of geostrategic crises?
Is NATO, relying on the banner of “collective security,” capable of acting quickly and adaptively? And finally, is there an alternative form of “NATO-plus” that would allow Ukraine to be supported in practice, at least de facto, without full membership?
These questions have resonated not only within think tanks but also touch the very essence of Europe’s security architecture. In particular, the Centre for European Reform (CER) in its June 2025 report “NATO summit 2025: Time to build a proper European pillar?” provides an in-depth overview of the transformations driven by the war in Ukraine and proposes new approaches to decision-making, the role of intermediary countries, and support models without formal membership.
How the War in Ukraine Has Called into Question the Mechanism of “Unanimous” Decision-making
The traditional veto right in NATO was designed to protect the sovereignty of its members, but in the context of war, its weight has become a disadvantage. Hungary, for instance, has repeatedly blocked initiatives to support Ukraine, citing insufficient protection of the Hungarian minority in Ukraine, the timing of joint statements, or domestic political factors. The CER emphasizes that such actions have demonstrated how the fundamental principle of member autonomy has, in practice, become a tool for political blackmail.
At the Vilnius Summit in 2023, the concept of “adaptive unanimity” was presented for the first time: a mechanism whereby security-related decisions could be made by a majority, for example, 80%. Although the CER acknowledges that the likelihood of initiating the process of amending the Charter is currently minimal, the very fact that this alternative is under discussion indicates the collapse of the long-standing veto mechanism.
This paradox has become evident: the protection system proved useless when it came to the priority of protecting Ukraine and deterring Russia.
The Role of Mediator Countries: How the UK, Lithuania, and Türkiye Are Driving Decisions Forward
When formal mechanisms stall, a completely different kind of diplomacy begins to take shape. The CER highlights the growing influence of “Coalitions of the Willing” – individual NATO member countries that coordinate decisions outside official institutional channels.
The United Kingdom and Lithuania have emerged as leading proponents of a “NATO-plus” model. The UK, for instance, concluded bilateral agreements with Ukraine on air defense as early as 2023-2024, significantly strengthening Ukraine’s air capabilities. Lithuania, meanwhile, plays a key role in the Lublin Triangle – a trilateral alliance that enables member states to take on legally binding commitments to support Ukraine without necessitating formal NATO membership.
Other countries, such as Poland, Estonia, and Romania, have joined the Sky Shield initiative – a joint European air defense system that, in the context of Russian aggression, could eventually extend to cover Ukrainian airspace.
Türkiye occupies a more ambiguous position. While it has blocked NATO expansion due to its policies concerning Syria and Kurdistan, it has also supported Ukraine in the Black Sea and played a crucial role in grain export agreements. Analysts define Türkiye as a situational mediator – one that avoids formal coalition frameworks or air defense models but remains strategically important in realizing hybrid regional objectives.
New Formats without Official Membership: Is a “NATO-plus” Model Possible?
The “NATO-plus” format envisions a framework that provides de facto security guarantees without granting formal membership. Three components are responsible for the implementation of this model:
1. Integration into the air defense system. One example is the European Sky Shield initiative, which is capable of covering Ukrainian territory and is operated by European countries outside NATO’s formal structures. Supported by former NATO generals, this initiative has demonstrated that effective protection can be ensured without formal membership.
2. The creation of Weimar+. Launched in February 2025, Weimar+ functions as an informal intergovernmental coordination structure that includes France, Germany, Poland, the United Kingdom, Italy, Spain, and the European Commission. This group demonstrates a commitment to reaching an agreement outside the “big NATO.”
3. Coalitions of the Willing. Following the London summit in March 2025, the UK, together with a group of like-minded states, formed a coalition ready to support Ukraine after the anticipated peace process. These countries pledged not only to maintain sanctions but also to assume new military responsibilities. The June 2025 summit in The Hague showed that a number of these states are preparing concrete security measures without forming a formal alliance, yet with speed and determination.
In addition to these components, Ukraine is gaining access to key NATO structures without formal membership. It is already de facto integrated into a number of programs: the NATO-Ukraine Council, Joint Expeditionary Force (JEF), NAP (National Action Plan), and PESCO.
Ukrainian intelligence structures and combat aviation officers will have access to NATO’s overall tactical command within the European Sky Shield, which has been agreed with the participation of allies such as Poland and Slovakia. Thus, although it is not a member, Ukraine practically fulfills some of the duties and rights that constitute the institutional component of the Alliance.
The June 2025 NATO Summit in The Hague: Strategy, Challenges, Reality
The June 2025 NATO Summit in The Hague is one of the year’s key political events for the Alliance, which is under unprecedented pressure, both externally and internally. Held in a compressed “single-session” format, the summit was designed less to engage in deep strategic debate and more to project unity and resolve in the face of growing threats from Russia.
The key topic of the meeting was a joint initiative by Dutch Prime Minister Mark Rutte and US President Donald Trump to increase defense spending to 5% of GDP, with a clear division: 3.5% for heavy weapons and another 1.5% for cyber defense, logistics, and military mobility. This proposal had already been approved at the level of NATO member countries’ ambassadors ahead of the summit, forming the basis for its political approval.
However, the Alliance faces several systemic challenges. First, internal divisions. Spain has already publicly stated its disagreement with the 5% target, and other Western European countries, including France, Belgium, and Italy, have voiced their undisguised dissatisfaction with the excessively “militaristic” strategy.
A second major challenge is the unpredictability of Donald Trump, whose political volatility is widely seen as a threat to Alliance cohesion. For this reason, the summit was deliberately shortened to 2.5 hours to minimize opportunities for discord. Moreover, the Alliance was forced to act against the backdrop of growing war fatigue among the European population, budget constraints in the EU, and parallel efforts by the European Union to establish a €150 billion SAFE defense fund to reduce dependence on the US.
The reality at the moment is as follows: 32 countries, including Poland, Latvia, Canada, the Netherlands, and most Eastern European states, have already formally confirmed their commitment to the new defense spending target. Kyiv also remains among the key topics. The issues of supporting Ukraine, strengthening the eastern flank, and containing Russia dominated the agenda.
Ultimately, the 2025 NATO Summit in The Hague was not a demonstration of internal strength, but rather a ritual of political survival. The alliance is preparing for a decade defined by new realities: reinforcing its defense capabilities, advancing competitive strategic thinking, and deterring revanchist empires. Whether this meeting becomes the starting point for a new transatlantic treaty depends not only on the text of the final communiqué, but also on political will, which is sorely lacking in Europe today.
Therefore, we have a number of new changes and risks:
Flexibility versus unity. The transition to “adaptive unanimity” marks the de facto end of consensus diplomacy as an absolute principle. The system allows countries that block decisions, such as Hungary and Slovakia, to become outsiders without the right to hold back the entire Alliance.
A new agenda: Coalitions of the Willing. The United Kingdom, Lithuania, Poland, and France have demonstrated their readiness to form structures that carry out the Alliance’s tasks. This means that even simple agreements can launch NATO’s foreign policy without full coordination through the Council.
European autonomy. Initiatives such as SAFE, Weimar+, Sky Shield are more than symbolic. They signal that Europe is capable of acting independently, even after the 5% defence spending commitment. Despite the difficulties, these projects could form the core of a “European platform” within NATO.
The US, Trump, and unpredictability. Trump’s presence has introduced an element of instability. His conditions are mandatory 5% defense spending and a refusal to discuss Ukraine. Part of the solution was to agree on a short communiqué, formal and symbolic.
Risks of escalation. Sky Shield and Weimar+, though initiated without formal membership, could provoke a Russian reaction. The adoption of a 5% defense budget may also lead to an overheating of national budgets.
Expectations for the new phase of the Alliance’s existence:
1. Unanimity is becoming obsolete. The blocking mechanism has turned from a guarantor of equality into a brake in wartime. The transition to adaptive consensus is the first step towards reform.
2. Mediators are surpassing institutions. The United Kingdom, Lithuania, and Türkiye are demonstrating the possibility of moving forward without the entire Alliance. This undermines the role of traditional institutions.
3. NATO-plus is no longer a utopia. European initiatives prove that guarantees are possible without membership. Ukraine is already effectively integrated.
4. The 2025 summit in The Hague is the point of no return. The Alliance’s adaptive architecture is almost a reality.
5. Europe can become a key player. If it continues its military course, it can become a regional leader capable of acting without the full participation of the US.
6. There is still a long way to go. The dominance of coalitions is a step forward, but the question remains: will countries dare to provide an official package of guarantees to the Ukrainian state, and will the Alliance remain united even under Trump’s influence?
Ukraine has become not only a driving force behind NATO’s transformation, but also an instrument for its implementation. The Alliance is evolving from an “all-or-nothing” approach to a multi-layered structure of adaptive guarantees. In this new reality, NATO is no longer a club bound by unanimity, but a flexible network of alliances, where even non-members can receive practical support.
Bohdan Popov, head of digital at the United Ukraine Think Tank, communications specialist, and public figure