EU-Beistandsklausel und Solidaritätsklausel im Lichte der Terroranschläge von Paris

This article analyses the applicability of the EU mutual defence clause (Article 42(7) of the Treaty on European Union) as well as the EU solidarity clause (Article 222 of the Treaty on the Functioning of the European Union) in light of the attacks in Paris committed by the so-called Islamic State (IS) on 13 November 2015. These two EU treaty norms provide the legal basis for a common response by the EU Member States in cases where an EU country is the victim of an armed aggression or a terrorist attack respectively. The analysis focuses on the factual requirements of the applicability of these provisions, their procedural mechanisms and the legal consequences resulting from the invocation of these clauses. In particular, the term »armed aggression« under Article 42(7) TEU will be subject to a closer examination. The article concludes that the scope of application of the EU's mutual defence clause is legally different from the solidarity clause. Furthermore, the analysis finds that, whereas the mutual defence clause contains a strict obligation of the EU Member States to provide military assistance to the state that has been subject to an armed aggression, the solidarity clause grants a wide scope of discretion to choose the mechanisms deemed adequate to fulfil their obligation of solidarity. The article argues that – contrary to France's view – the mutual defence clause, interpreted with respect to the current state of customary international law, does not apply to the Paris attacks committed by a private terrorist group. However, the reactions of the other EU Member States to the activation of that clause by France might provide state practice and opinio iuris to trigger the development of a new rule of customary international law.