The clause states that if a member of the EU is faced by “armed aggression,” other members have an obligation to come to its “aid and assistance by all the means in their power.” The clause does not specify whether such aid includes a military response, and contains language relevant to neutral states such as Austria and Ireland.
The gaming out will be conducted in the EU’s Political and Security Committee, which is composed of senior EU diplomats.
Most EU members also belong to NATO and so are covered by its Article 5 mutual defense clause, which does refer explicitly to the use of military force to aid other signatories.
But transatlantic tensions, including U.S. President Donald Trump’s threats of seizing Greenland, have shaken faith in Article 5 and sparked renewed interest in EU security arrangements. Aspiring members of the bloc now increasingly mention security as an incentive to join the bloc, alongside wealth and stability.
Another factor driving interest in 42.7 is the increased risk of attack against EU states.
After being targeted by drones launched from Lebanon in March, Cyprus in particular has voiced interest in exploring how Article 42.7 would work in practice, the senior official said. A summit of EU leaders takes place in Cyprus next week.