The EU’s “Mutual Assistance Clause” is designed to ensure an EU-wide response in case of an act of armed aggression against any member state. Yet, the treaties are unclear about what a response should look like in practice, even though the unique character of individual member states is maintained. As the risk of armed aggression has increased globally, there is a need to ensure that the Union’s response mechanisms can adapt to unique and grave circumstances. 

The idea that any of the European Union’s (EU) member states could face a direct military attack has not traditionally been at the forefront of strategic thinking on EU security and defence. For example, the 2003 European Security Strategy boldly proclaimed that ‘Europe has never been so prosperous, so secure nor so free’. While the Balkans was cast as a ‘reminder that war has not disappeared from our continent’, the Strategy did not assume that any existing EU member state could be the victim of military aggression. 

This assumption had changed by the time the EU Global Strategy was published in 2016. It made clear that EU member states had an obligation to each other for mutual assistance and solidarity in case of a major crisis or conflict. France’s invocation of the “Mutual Assistance Clause” following the 2015 terrorist attacks on Paris led to a greater focus on what it would mean to be the victim of armed aggression inside the EU. In combination with Russia’s illegal seizure of Crimea in 2014, the heightened prospect that an EU member state could be subjected to a terror or hybrid campaign highlighted the need to “protect Europe and Europeans”. 

While NATO was underlined in the EU Global Strategy as the ‘primary framework’ for collective defence, it also recognised that NATO might not be able to respond to all forms of aggression. The Article 5 security guarantee embedded in the Washington Treaty, whereby each ally has an obligation to defend the other from military aggression, could not entirely respond to attacks below the threshold of military force. In any case, the EU had to think about the possibility of a response in case of armed aggression against those EU member states that are not part of the NATO alliance including Austria, Cyprus, Ireland and Malta.

In 2022, with Russia’s full-scale invasion of Ukraine, the EU’s Strategic Compass for security and defence raised the threat level still further for the Union. The Compass – the Union’s first-ever defence strategy – mourned the return of power politics and the erosion of multilateralism, calling the growing strategic competition facing the Union as a ‘direct attack on the European security order’. The Compass, released as Russia had already invaded Ukraine, called for a quantum leap forward in how member states collectively respond in cases of armed aggression. 

The Compass was based on a threat analysis conducted in November 2021 that already foresaw the challenge posed by direct threats to the EU. The Analysis – while confidential and not in the public domain – made reference to the threats posed by state and non-state actors, but it did not stress the risks from direct military aggression towards the Union. By the time the Threat Analysis was updated in December 2022, this assumption was made more forcefully in the context of Russia’s invasion of Ukraine. 

However, the Compass is relatively ambiguous on what response could be expected in case any member state invokes Article 42(7) TEU, save for a call for EU unity and the need for more frequent exercises. In fact, even before Russia’s invasion of Ukraine the EU had already conducted such exercises, most notably under the French Presidency of the Council of the EU, with a focus on hybrid, space and cyber threats.

Undoubtedly, the risk from a direct military attack on the EU is higher today than it has been in the past, and Article 42(7) TEU is designed to ensure a collective response to such as threat. Specifically, TEU makes clear that Article 42(7) can be triggered in case of an act of armed aggression against an EU member state, but on condition that the attack originates from outside the EU. In case an EU member state invokes the mutual assistance clause, all other members would have ‘a legally binding obligation […] to provide assistance’.  This would apply to neutral states such as Austria too. 

What is unclear, however, is what the precise response would be. There is no prescribed response to an act of armed aggression, and any response would have to be tailored to the specific case. The first obvious form of implementing Article 42(7) TEU would be political solidarity with the victim, but it should be assumed that the full range of responses would be required including military and humanitarian aid. Of course, each state would have to decide on their own response level within an EU context. 

Indeed, the Treaties make clear that the obligation of aid to any member state should occur within ‘the means in their power’ and should not ‘prejudice the specific character of’ their security and defence policies. This means that each state must act in accordance with their own means and national perspectives. Of course, this would also apply for other member states in case a neutral or non-NATO state is attacked. In this sense, there is a clear need to work on common EU approaches to Article 42(7) TEU-type incidents through exercises, a common threat analysis and the strengthening of relevant EU bodies. 

Risikobild 

Read now (German langauge version)