On 17 November 2015, during the EU Foreign Affairs Council (Defence format) in Brussels, France invoked the EU’s mutual assistance clause in Article 42(7) TEU in response to the 13 November Paris attacks.
Unlike NATO Article 5, Article 42(7) is implemented bilaterally: each member state decides how to provide aid and assistance. Ministers expressed unanimous support and readiness to help.
Why it matters: it was the first activation of Article 42(7), setting a precedent for EU solidarity mechanisms in major security crises.