How Ukraine is reshaping NATO

In May 2025, during NATO's “Hedgehog” exercise in Estonia, a team of ten Ukrainian drone operators successfully simulated the destruction of 17 armoured vehicles, and by conducting about 30 strikes effectively “neutralized” two NATO battalions in about half a day. This simulation exposed critical gaps in the Alliance's preparedness for modern warfare: the Ukrainian operators, applying their most recent experience directly from active combat, had brought to the table the expertise that NATO had spent years rather theorizing about but had never experienced at this intensity.

This scene is an illustration of the fundamental shift in NATO’s relationship with Ukraine. Kyiv has a long track record of being a committed partner, the only non-member state that has participated in all major NATO-led operations and missions. Since the Russian full-scale invasion of 2022, Ukraine has received unprecedented assistance from the Alliance and its member states. Now, in the fifth year since the full-scale invasion, we can state that Ukraine has become a transformative factor for NATO itself: what began as an emergency response to the full-fledged war at NATO’s borders has now evolved into a set of unprecedent changes to the Alliance's institutional architecture, operational practices, and conceptual frameworks.

Institutional innovations

Largely thanks to the structures in place to closely cooperate with Ukraine, allied forces receive military experience from the ongoing modern high-intensity warfare. Ukrainian innovations in drone warfare, electronic combat, and integrated defence are rewriting NATO approaches faster than the Alliance's traditional planning cycles allow. It remains to be seen whether the Ukrainian factor is systemically incorporating adaptability into NATO, or whether these structures and approaches will prove to be case specific.

Nevertheless, the structures NATO has built since 2022 constitute institutional innovation with little to no precedent in the Alliance's history. They grant a non-member state (Ukraine) a strong political standing and operational integration. Notably, most of this was achieved while keeping NATO away from being a party to the ongoing war – a concern that blocked progress in cooperation more than once.

The biggest visible shift in Ukraine’s relationship with NATO came with the Vilnius summit in July 2023, when NATO replaced the NATO-Ukraine Commission with the NATO-Ukraine Council, or NUC. In this new joint body, Ukraine now sits alongside all member states as an equal participant, with the right to convene crisis consultations. This represents the first time NATO has granted an aspiring member such status. While the NATO-Russia Council, established in 2002, was also built on equal participation, Russia was treated as a peer requiring strategic accommodation (practical cooperation was suspended following Russia’s illegal and illegitimate annexation of Crimea in 2014, and there were no meetings following Moscow's full-scale invasion of Ukraine in 2022). The NUC is openly presented as part of a “package of support bringing Ukraine closer to NATO”.

A year later, at the Washington summit in July 2024, allies established the NATO Security Assistance and Training for Ukraine (NSATU). This represents NATO's first operational command coordinating assistance to a non-member at war. It has a very particular architecture, with headquarters in Wiesbaden (Germany) and logistics hubs in Poland and Romania, thus operating exclusively on allied territory. Streamlining is key as the initiative has absorbed the responsibilities from multiple ad hoc bilateral and multilateral initiatives and programmes that had limited coordination. Now, NSATU creates a single mechanism for overseeing the training of Ukrainian armed forces at allied facilities, providing long-term force development support, and coordinating equipment donations, transfers and repair.

The Joint Analysis, Training and Education Centre (JATEC) identifies and supports the applications of lessons learned from Russia’s war against Ukraine. It was inaugurated in Bydgoszcz, Poland in February 2025. This is a one-of-a-kind civilian-military institution between NATO and a partner state, with Ukrainian and allied personnel working together. JATEC provides systematic real-time analysis of the battlefield experience of the Ukrainian defence forces, bringing Kyiv’s expertise into NATO’s training, education and analysis ecosystems. This has created compressed feedback loops from battlefield to doctrine. The first year has brought practical results that are already deployed: JATEC's counter-drone work produced the Tytan interceptor and AI-enhanced Alta Ares guidance system, which are now integrated into Ukrainian interceptor platforms with confirmed combat engagements. Ukrainian representatives also participated for the first time in “Loyal Dolos” 2025, a NATO Article 5 exercise integrating combat experience directly into Alliance preparedness.

Finally, The Prioritised Ukraine Requirements List (PURL) was formalized in July 2025. It represents the first mechanism in which NATO allies systematically finance US-manufactured weapons for transfer to a non-member at war. Rather than fragmented bilateral donations from national inventories, PURL creates a standing, repeatable procurement cycle: Ukraine identifies priority packages of approximately 500 million US dollars each. European allies and Canada fund them and the United States delivers from its stockpiles. This is also a rather unique format as it reflects and resolves the internal challenges that NATO was facing. By embedding procurement decisions within a multilateral institutional framework, PURL provides a degree of insulation from the volatility of political cycles: commitments are made collectively, announced publicly, and tied to NATO's coordination architecture rather than to the discretion of an individual government. Notably, PURL did not replace the Ramstein format but rather up-scaled its work, systematizing more predictable, high-volume procurement matched to battlefield requirements. Since its launch, PURL has supplied around 75 per cent of all missiles for Ukraine's Patriot batteries and 90 per cent of the missiles used in other air defence systems. NATO allies and partners have already pledged more than four billion dollars under the PURL framework.

Towards integration

Institutional structures only matter as they succeed to produce operational delivery. In Ukraine's case, the transformation is visible across three interconnected dimensions: how the country is reforming its defence institutions, how it participates in Alliance exercises, and how it is achieving interoperability under conditions that no NATO partner and/or aspirant has previously faced.

The Annual National Programmes (ANP) are another important instrument for guiding aspirant NATO countries through the reforms required for membership: democratic civilian control, defence institution building, and interoperability standards. Historically, all countries that joined NATO did so through the Membership Action Plan (MAP) and ANP process in peacetime conditions. Ukraine appears to be the first aspirant to implement an ANP under conditions of an active large-scale war, a distinction with no clear parallel in the Alliance's enlargement history.

At the 2023 Vilnius summit, allies took two consequential decisions regarding Ukraine's accession path: the MAP requirement was dropped, converting Ukraine's path to NATO from a two-step process to a one-step process, with the adapted ANP becoming the sole instrument for tracking accession readiness. The adapted format, endorsed at the November 2023 NATO-Ukraine Council meeting of foreign ministers, was explicitly redesigned to reflect the conditions in which Ukraine has to operate. Adapted ANPs are much shorter, focused on key reforms (previously, ANPs would have 80 to 100 pages, while the first adapted version was only nine), and complementary rather than duplicative of Ukraine's EU commitments.

Crucially, the implementation assessment is much less of a bureaucratic exercise. The quality of institutional reforms in the defence sector during an active war has immediate and visible effects on Ukraine forces, creating a compressed feedback loop between battlefield performance and reform priorities. This arguably inverts the traditional model into one in which the operational reality informs the drafting of the next iteration of a document.

Before 2022, Ukrainian participation in NATO exercises (such as “Rapid Trident” or “Sea Breeze”) followed a regular pattern in which Ukraine acted as a partner learning NATO procedures. Now that relationship has fundamentally shifted. The “Hedgehog” exercise held in Estonia in May 2025, and involving more than 16,000 troops from 12 NATO countries, crystallized the change. Ten Ukrainian drone operators rendered two NATO battalions combat-ineffective in a single day. NATO forces were assessed as moving with little concealment, hardly able to make rapid decisions, while Ukraine’s “Delta” battlefield-management system quickly detected and neutralized them. In September 2024, Kyiv for the first time joined NATO's annual Counter-Unmanned Aircraft System Technical Interoperability Exercise in the Netherlands, with the exercise designed to learn from Ukraine's experience in countering small drones.

In March 2026, the Netherlands became the first NATO ally to systemically embed drone and counter-drone units across every combat formation in its army. This transformation follows directly from the Ukrainian institutional innovation. Already in 2024 Ukraine established Unmanned Systems’ Forces as the first separate branch in the world that uses airborne, sea surface and underwater, and ground-based unmanned and robotic systems in combat operations. Thus, Ukrainian innovations are now being incorporated directly into NATO exercise planning, and translated into structural changes within NATO member states.

Decisive questions

Ukraine is simultaneously operating donated western platforms like Patriot air defence systems, HIMARS, F-16s, Leopard and Challenger tanks alongside legacy Soviet-era equipment, all whilst actively fighting. This de facto technical interoperability was not planned: it emerged under combat necessity, compressing into years a transition that NATO's traditional planning frameworks assumed would take decades. The formal architecture to sustain and systematize it was put in place later: in September 2023, Ukraine and NATO agreed on a concept for interoperability, so that Ukrainian defence planners would incorporate interoperability requirements into their long-term capability development plans for the country’s defence and security sector.  As part of this interoperability roadmap, NATO defence planners advised Ukrainian officials on interoperability requirements and assisted in developing a set of initial guidelines that were presented at the 2024 Washington summit.

What distinguishes this process from any previous NATO enlargement trajectory is that interoperability is being exercised under active warfare. While other NATO applicants had the time and institutional capacity to build long-term systemic transformations across all dimensions as well as apply immediate, rather operational changes, Ukraine is unable to pause the combat operations for comprehensive institutional reform. Thus, Kyiv pursues a dual-track approach: immediate operational adaptations that help survive the war, alongside selective long-term reforms tied directly to urgent needs, inter alia - defence procurement reform.

Ukraine's extensive modern battlefield experience has forced NATO to re-evaluate approaches to security and defence on a scale and speed unprecedented since the Alliance's founding. This has focused on drone warfare, continuous electronic warfare adaptation, and new planning frameworks built around short, high-intensity engagements. NATO members now have to revise their equipment stockpiles, industrial base sustainability, mobilization capacity and policy. In addition, Russia's adaptation across more than four years of high-intensity combat has simultaneously provided NATO with a detailed intelligence picture of a peer adversary's actual operational performance.

Five years on, the distance travelled by NATO and Ukraine is impressive. While 2022 saw ad hoc bilateral donations and improvised coordination, 2026 has seen such initiatives as NUC, NSATU, JATEC, PURL, and adapted ANPs become integral parts of an ecosystem with no precedent in NATO’s history, and one that has already delivered measurable results. Ukraine’s battlefield lessons are feeding into doctrines within months, procurement cycles are replacing fragmented bilateral initiatives, and Ukrainian tactical expertise is reshaping how allied forces train and fight on the ground.

In addition, this war has been a decisive catalyst in driving NATO members towards the five per cent GDP defence spending commitment agreed at The Hague summit in June 2025 (a target long demanded by the United States). The structure of that commitment ensures that up to 1.5 per cent is distributed domestically towards critical infrastructure protection, cyber defence, civil preparedness, innovation, and industrial base development, meaning more security dividends (and potentially workplaces) for each individual ally.

Yet the decisive questions remain open: how powerful is the inertia of the conceptual and institutional changes caused by the Ukrainian factor? Multidimensional cooperation with Kyiv has demonstrated that NATO can adapt faster than its own initial design had assumed. Whether that adaptability is now permanent or was rather caused by crisis is what the coming years will reveal. The burning issue for this author as a Ukrainian is how long will this current quasi-integration without membership last while Ukraine’s experience is now shaping the Alliance’s doctrines and translating into defence reforms in the member states? Would peacetime bureaucratic gravity cause setbacks in what is now intense cooperation?

One thing, however, is already beyond question: European and transatlantic security is no longer something NATO does for Ukraine. It is what NATO and Ukraine are building together, with Kyiv being a critical asset in this equation.

 

 

Kseniya Sotnikova is an Ax:son Johnson Fellow with the Center for European Policy Analysis (CEPA). She has experience in Ukrainian public service, mainly at the National Security and Defence Council dealing with political and security cooperation. She has also worked at the EU Advisory Mission (EUAM Ukraine) focusing on civilian security sector reform.