Why Article 5-style guarantees for Ukraine may not work

A consensus is forming among Western leaders on what security guarantees Ukraine should receive once the fighting stops. The phrase of the moment is 'Article 5-like', borrowed from NATO's mutual defence clause. Giorgia Meloni, Italy's prime minister, raised the idea in March 2025. Donald Trump's team pushed a variant in August, envisioning a United States security pledge outside the NATO framework. Emmanuel Macron, France's president, went furthest: he convened 26 European partners in Paris in September to discuss a post-war 'reassurance force'. The language sounds decisive. It is not.

The grey-zone problem on NATO's own soil

Russia is already testing the boundaries of collective defence inside NATO territory, and the alliance's signature clause has not once been invoked in response. On 10 September 2025, roughly two dozen Russian-manufactured drones entered Polish airspace during a wider strike on Ukraine. Polish fighter jets shot down those assessed as threats. Warsaw activated Article 4 of the North Atlantic Treaty, which triggers consultations, not automatic military action. No ally proposed moving to Article 5.

In the weeks that followed, Denmark temporarily closed several airports after repeated drone sightings. French naval personnel boarded a tanker suspected of belonging to Russia's shadow fleet and of involvement in the drone disruptions. Germany reported coordinated drone flights over a refinery, a shipyard, a university hospital and the Kiel Canal. Across the Baltic, months of damage to undersea cables and energy infrastructure deepened alarm. Each incident was serious. None clearly met the legal threshold of an 'armed attack' that would activate Article 5.

That gap between provocation and formal trigger is precisely the vulnerability that any post-war arrangement for Ukraine would inherit, only in a more dangerous form. Outside NATO's integrated command structure, without pre-agreed rules of engagement or standing forces, an Article 5-like promise would be slower and weaker than the original.

What Article 5 was actually built for

The North Atlantic Treaty was drafted in 1949, when the threat was visible and massed: Soviet tank armies across the Inner German Border. Article 5 establishes that an armed attack against one ally is an attack against all, but it then requires a political process. Consultations come first. Each member decides for itself what constitutes an armed attack and what response it deems necessary. The clause was written for columns of troops, naval bombardments, aerial bombing runs. It was not written for drones that appear for a single night, or for vessels that sever undersea cables then sail away, or for cyberattacks that disable infrastructure without a shot being fired.

Russia has studied this design carefully. Its operations in the Baltic and along NATO's eastern flank are calibrated to sit just below the threshold. The ambiguity is not accidental. It is the strategy.

The Budapest precedent: assurances without enforcement

Ukraine has been here before. In 1994, under the Budapest Memorandum, Kyiv surrendered the world's third-largest nuclear arsenal in exchange for 'security assurances' from Russia, the United States and the United Kingdom. Those assurances were political commitments, not legally binding obligations. When Russia seized Crimea in 2014 and fuelled conflict in Donbas using soldiers without insignia, the ambiguity of the operation itself became a debating point about whether the assurances even applied. Even had Ukraine been inside NATO at that moment, the deniable nature of the aggression would have raised questions about whether Article 5 covered the situation. Eight years later, Russia abandoned ambiguity entirely and invaded in force.

The lesson, for those inclined to draw one, is that non-enforceable promises and arguments over thresholds do not deter a determined aggressor. Guarantees that require consultation before action are guarantees that can be argued away.

Ukraine as security provider, not just recipient

One assumption underlying the Article 5-like discussion is that Ukraine is a security consumer, a country that needs protection. That assumption is outdated. After the Polish drone incursion in September, allied governments began asking Kyiv for counter-drone expertise. Ukrainian specialists have already deployed to Denmark to share methods for fusing sensor data, electronic jamming and low-cost interceptors. NATO officials now acknowledge publicly that European forces must learn to defeat cheap drones without launching missiles that cost hundreds of thousands of euros each. Ukraine has spent three years learning exactly that, at terrible cost, and has become competent in a domain where many European militaries are still catching up.

This shift matters for how guarantees are designed. A country that contributes to European security needs a different kind of arrangement from one that simply receives it. The mechanism should reflect Ukraine's capabilities, not merely its vulnerabilities.

An alternative framework: five pillars

A proposal gaining attention among security analysts, outlined most recently by the president of the Transatlantic Dialogue Center, argues that Ukraine needs a mechanism that triggers action automatically rather than after collective deliberation. The framework rests on five elements.

• Automatic triggers: a legally ratified 'if-then' mechanism that activates within hours when specific markers are met, including state-origin drones or missiles entering Ukrainian airspace, mass drone incursions into border regions, and destructive cyberattacks or sabotage against designated critical infrastructure. The initial response, both military steps and heavy sanctions, would be automatic. Consultations would adjust the response, not decide whether one occurs.
• Joint aerial and maritime shield: persistent airborne radar and maritime patrol coverage over Ukrainian skies and adjacent seas, fusing sensors from low to high altitude, with delegated rules for engaging drones along agreed corridors. The test, proponents argue, is economic: European defence must make Russian drone raids expensive for Moscow, not for European capitals.
• Visible presence and forward logistics: building ammunition, spare parts and maintenance hubs in Poland and Romania with a standing air bridge into Ukraine before any ceasefire, then rotating multinational detachments through Ukrainian ports and airfields afterwards. The aim is not permanent bases but ensuring that any renewed attack draws in several capitals immediately.
• Intelligence compact: moving from ad hoc sharing to an institutional arrangement that integrates satellite, signals, open-source and battlefield sensor data into near-real-time products shared with Ukraine. Fast attribution matters because the right to defend yourself depends on what you can prove, and deterrence depends on an adversary knowing you can prove it quickly.
• Production deal: multi-year funding anchored in co-production of drones, air-defence components and artillery rounds inside Ukraine, alongside European and American plants producing the high-end systems both Ukraine and Europe still lack. Guarantees tied to contracted output, not to communiques.

None of these elements copies the letter of Article 5. Together, they attempt to address a different kind of threat with tools designed to counter it.

The political obstacles

Automatic triggers sound efficient. They are also politically difficult. No government, least of all in Washington, readily surrenders the discretion to decide when and how its forces are committed. Article 5's consultation requirement exists precisely because sovereign states will not cede that decision to a mechanism. Asking the United States, in particular under Trump, to ratify a treaty-level obligation that commits American forces to automatic action in Ukraine would face steep opposition in Congress and the White House alike.

European governments have their own reservations. A joint air shield over Ukraine would require allied aircraft to patrol airspace that Russian missiles and drones cross regularly. Rules of engagement that permit shooting down incoming drones create a risk of direct confrontation with Russian forces, something several European capitals have spent three years trying to avoid. Rotating multinational detachments through Ukraine after a ceasefire would place Western personnel on the ground in a country where a single escalation could pull several nations into conflict simultaneously. That is the point of the proposal. It is also the reason it will face resistance.

The production deal may prove the most feasible element. Several European governments and Ukraine have already begun discussing joint manufacturing of drones and ammunition. Co-production creates economic interdependence, which is its own form of guarantee: countries are more likely to defend a partner whose factories supply their own military. But multi-year funding commitments require legislative approval in multiple parliaments, and the history of European defence procurement is littered with joint projects that collapsed under cost disputes and national preferences.

What the incidents reveal about alliance cohesion

The recent Russian drone flights over Poland and Germany, the shadow fleet operations near Denmark, and the Baltic cable damage have done something useful: they have exposed the limits of the current collective defence framework in real time, not in theory. Each incident forced the affected country to respond nationally, with NATO consultation following afterwards. The alliance provided intelligence and political support, but the operational response was Polish, German, Danish or French. That is how Article 5 works in practice. The alliance confirms an attack has occurred and each member decides what action to take. For incidents below the threshold of armed attack, the mechanism does not even reach that stage.

Ukraine, outside the alliance, would face this gap with even less institutional backing. An Article 5-like promise outside NATO's command structure, without the integrated air defence, shared logistics and unified planning that the alliance provides its 32 members, would be a statement of intent rather than an operational guarantee.