Phoenix 24
A promise becomes real only when tested.
Brussels, February 2026
Europe’s mutual defence clause has always lived in a curious space: strong on paper, thin in operational muscle, and politically awkward in a continent that outsourced deterrence for decades. This week, the European Union’s top military representative, General Seán Clancy, argued that making the clause usable should focus on situations “below the threshold” of NATO’s collective defence trigger. The subtext is blunt. If the hardest scenario still points to NATO, then Europe’s own clause must prove its value where pressure builds slowly, ambiguity dominates, and time is the adversary.
The legal spine is Article 42.7 of the EU treaties, a mutual assistance obligation when a member state suffers armed aggression on its territory, paired with language that points back to the right of self defence under the United Nations Charter. The clause is deliberately wide, “by all the means in their power,” yet it is also deliberately constrained. It does not erase the specific security and defence character of certain member states, and it must remain consistent with commitments under the North Atlantic Treaty for those who are allies there. In practice, that means the clause carries political weight, but it does not automatically produce an integrated plan, a command chain, or a standardised package of capabilities.
That gap between obligation and execution is why the clause is often compared to NATO’s Article 5 and almost always found wanting. NATO’s deterrent has been historically anchored in the United States, both in capabilities and in the credibility that those capabilities will be used. NATO also has mature operational plumbing: planning cycles, force structures, interoperability routines, and the institutional habit of translating treaty language into deployable options. The EU has pieces of this architecture, but not the same reflexes, and not the same clarity about what “help” must look like when clocks are running.
The contrast becomes sharper when you look at the record of activation. NATO’s Article 5 has been invoked only once, after the September 11 attacks, and it did not function as a single dramatic switch so much as a political decision that opened pathways for allied support. The EU’s Article 42.7 has also been activated only once, by France after the Paris attacks in November 2015, and the responses were largely bilateral and improvised rather than centrally orchestrated. Those two episodes reveal the real design of both clauses: they are political accelerators, not automatic war machines, and their effect depends on whether members can convert solidarity into usable assets.
Clancy’s “below Article 5” framing is therefore less a technical distinction than a strategic assignment. Hybrid coercion, sabotage, cyber disruption, maritime harassment, and proxy pressure are where adversaries can impose costs without crossing the neat legal line of armed attack. In that band of grey zone competition, hesitation is contagious and time is punitive. If the EU cannot coordinate responses there, it risks being structurally slow in precisely the environment where speed and coherence matter most, and it risks forcing every incident into the NATO frame even when the best answer is political, economic, legal, and security combined.
That is also why Ursula von der Leyen’s call in Munich to “bring the clause to life” landed as more than rhetoric. Her argument was essentially institutional: a treaty obligation has weight only when anchored in trust and capability, and capability is not a slogan. Europe’s defence debate has been accelerated by Russia’s full scale war against Ukraine and by the recurring anxiety that the transatlantic guarantee could become more conditional. Even when officials insist that commitments remain firm, the mere presence of doubt changes behaviour: budgets shift, procurement priorities reorder, and the demand for European redundancy rises.
The operationalisation effort now being discussed is tied to a broader readiness agenda aimed at the end of the decade. The European Commission is pushing instruments that encourage joint procurement to close capability gaps faster and cheaper, and the current plan includes a large lending facility for collective purchases across priority areas that track modern combat realities. Ammunition stockpiles, drones, air defence, and strategic enablers are not glamorous, but they are the hard currency of resilience. Clancy has described an implementation phase across these capability lanes, noting that some move faster where industrial bases are mature or where Ukraine’s battlefield lessons compress the learning curve, particularly in drones and space enabled assets.
Still, there is a risk of mistaking spending for readiness. Procurement without integration produces warehouses, not deterrence, and national investments that do not interlock can become parallel projects with limited cumulative effect. SIPRI’s long term data on European defence trends has repeatedly shown how fragmented acquisition can dilute value, while operational experience from NATO planning culture shows that readiness is a system, not a collection. The EU’s challenge is to build a credible mechanism that can decide quickly, attribute confidently, and deliver assistance that is visible enough to deter but calibrated enough to avoid escalation traps.
A serious “below Article 5” doctrine would also require clean political rules. When is an incident hybrid rather than criminal, and who says so with legitimacy. What threshold activates collective assistance, and what is the menu of responses that a member can request without triggering months of negotiation. How do neutral or militarily non aligned states participate without turning the clause into a symbolic gesture. Analysts at institutions like the Center for Strategic and International Studies have argued that Europe’s autonomy is constrained less by intent than by the mechanics of mobilisation, while Indo Pacific strategists at places like the Lowy Institute have warned that deterrence fails when ambiguity is left unmanaged. In other words, a clause without an operating concept is not a shield, it is a debate.
Europe is not trying to replace NATO in the hardest war scenario, and the current messaging implicitly accepts that reality. The sharper question is whether the EU can build a parallel layer of collective defence logic that works when threats are engineered to remain deniable, legally messy, and politically inconvenient. If the mutual defence clause becomes a reliable tool for hybrid and crisis response, it strengthens NATO by reducing overload and sharpening division of labour. If it remains a ceremonial promise, it becomes a vulnerability that adversaries can probe, not because the words are weak, but because the system behind the words is unfinished.
Más allá de la noticia, el patrón. / Beyond the news, the pattern.