The European External Action Service, under Kaja Kallas, is advancing three different scenarios for implementing the European Union’s mutual defense clause, though no common understanding exists yet among European Union member states. More than a decade after its first and only activation, Article 42.7 of the Treaty on European Union, considered the closest European equivalent to NATO‘s Article 5, is gaining clearer “user guidelines” for the first time.
According to a European External Action Service (EEAS) document seen by ERTnews, Brussels is launching a series of scenario-based exercises aimed at developing a common understanding of how to activate and practically implement the heaviest and most unexplored provision of European security architecture. The document, drafted in response to requests from several member states for specific discussion on the article’s implementation, begins with the disarming admission that “currently there is no common understanding” among member states regarding the invocation, activation and implementation of Article 42.7, nor regarding the role that the High Representative, Council and Commission could play in case of its activation.
The provision itself is categorical, stipulating that if a member state suffers armed attack on its territory, other member states “shall have towards it an obligation of aid and assistance by all the means in their power.” This is a legally binding obligation and, as the EEAS clarifies, its scope covers attacks by non-state actors, such as cyberattacks or inadvertent escalation of hybrid campaigns. However, the Treaty provides no implementation procedure and no role for EU institutions. The decision to invoke it belongs exclusively to the affected state, which must itself determine what kind of assistance it needs, military or political.
Three scenarios on the table
To fill this gap, the EEAS proposes scenario-based exercises at the Political and Security Committee (PSC) level and the Foreign Affairs Council in Defense Ministers composition. The document describes three scenario options: hybrid attack escalating to Article 42.7 activation, armed attack leading to clause activation, and (the most politically sensitive) armed attack leading to simultaneous activation of EU Article 42.7 and NATO Article 5.
The document also outlines the role the European Union could assume if requested, including: support in attributing responsibility for the attack, creating operational picture, recording and communicating the affected state’s needs, coordinating assistance and mobilizing EU mechanisms and tools, including countermeasures like sanctions. Coordination could be undertaken by High Representative Kaja Kallas herself (Renew, Estonia), utilizing structures like the EEAS Crisis Response Mechanism, the ARGUS system and the European Commission’s Emergency Response Coordination Centre.
The 2022 text
The endeavor is not entirely unprecedented. In January 2022, the EEAS had distributed to the PSC a corresponding working document (marked EEAS(2022)13, titled “Strengthening EU mutual assistance in case of armed attack against a member state”), which has since become partially accessible in the Council’s public document registry. The new document seen by ERTnews constitutes an update of that review, with the critical difference being the proposed next steps. Then the goal was mapping the framework; today it’s moving to the implementation phase.
The file’s history contains a harsh irony, recorded in the document itself. The major cyber scenario exercise planned for the Foreign Affairs Council in early 2022 never took place, as its scheduled date coincided with the start of the full-scale Russian invasion of Ukraine.
The file’s trajectory
The clause has been activated only once, by France on November 16, 2015, following terrorist attacks in Paris. Within weeks, most member states increased their contributions to existing missions and operations, allowing Paris to redeploy forces to its national territory and the Coalition against “Daesh” (Islamic State of Iraq and the Levant). This was followed by scenario discussions at ministerial level in 2019 with hybrid scenarios, three PSC exercises in 2021 on hybrid threats, cyberattacks and the relationship with the solidarity clause of Article 222 TFEU, plus a new cycle in 2022 that even included a workshop on implementing Article 42.7 in Space.
The urgent nature under Cyprus Presidency
In 2024, the file acquired urgent character and the Cypriot Presidency made it their flagship. The Middle East crisis and the transit of Iranian drones targeting British bases in Cyprus (a member state outside NATO, without access to Article 5’s umbrella) raised the question in terms that ceased to be theoretical. At the informal Summit in Nicosia on April 23-24, Article 42.7 was placed on the leaders’ table as a standalone issue for the first time. Kaja Kallas briefed European leaders on ongoing work, while Cyprus President Nikos Christodoulides publicly set the bar, stating that “we must formalize the mutual defense clause into a structured operational mechanism” capable of turning political declarations “into predictable action.”
The follow-up was immediate. In early May, Political and Security Committee ambassadors conducted the first simulation of the article’s application in Brussels, focusing (according to Euractiv) on “practical aspects” – namely, the mechanism’s activation thresholds, tools that can be mobilized to support capitals, and potential obstacles.
Ambassadors were presented with two alternative scenarios for the EEAS role, while NATO was deliberately kept out of frame at this stage. Kallas’ Service wants to first clarify what EU tools are available in crisis situations before opening dialogue with the Alliance. On June 8, the file moved to the informal Defense Ministers meeting in Nicosia, while Defense and Space Commissioner Andrius Kubilius, who has emphasized that “Article 42, paragraph 7 is really critical,” shares this spirit. Beyond material readiness, the goal is “institutional defense readiness,” expressing the expectation that the “manual” will help institutions know the necessary actions in times of crisis.
Athens and Paris push the file forward
Beyond Nicosia, the file is mainly pushed by Athens and Paris. Greek Prime Minister Kyriakos Mitsotakis has emerged as the most persistent supporter of operationalization. Indeed, arriving at the Nicosia Summit, he reminded that he has been talking about “substantial upgrade and activation of Article 42.7” for “quite some time,” characterizing European countries’ support for Cyprus as “first practical proof that Europe can stand alone beside” its threatened members.
Later, in joint statements with French President Emmanuel Macron, both leaders characterized the clause as “reinforced concrete” and stronger than NATO’s Article 5, with Macron calling it “non-negotiable” (recalling that France is the only country to have invoked it). In his meeting with Commissioner Kubilius in early May, Mitsotakis returned to the topic, noting that Athens particularly looks forward “to making this Article operationally functional” and that the discussion must be public. Greek interest is not coincidental, as Greece was among the main inspirers of including the clause in the Lisbon Treaty, seeking an additional level of protection against a neighbor that belongs to NATO but not the EU.
On the opposite side, traditionally neutral member states (Ireland, Austria, Malta) are covered by the Treaty provision that the clause “shall not affect the specific character” of their security and defense policy. Even there, however, the ground is shifting. In Dublin, Foreign Affairs and Defense Minister Helen McEntee is currently pushing through the Cabinet the Defence (Amendment) Bill 2024, which abolishes the so-called “triple lock” – the requirement for approval from government, parliament and UN Security Council for any deployment of Irish forces abroad. The government cites Ireland’s mandatory withdrawal from Operation IRINI when the relevant Security Council resolution expired in May, arguing that the current regime allows any permanent member to tie the country’s hands with a veto. The opposition, led by Sinn Féin, denounces “serious erosion” of Irish neutrality, while over 400 academics call for the bill’s withdrawal in an open letter. Dublin is not abandoning neutrality, but clearly shows the wind’s direction.
The next milestone is transferring exercises to the ministerial level of the EU Foreign Affairs Council in Defense composition, as the document provides, with the final deliverable being the “user manual” for the three scenarios. Thus, it remains to be seen whether Article 42.7 of the EU Treaty will remain a dormant provision of Lisbon or become a credible deterrence mechanism.
