Obligation to Mutual Assistance Under Article 42(7) TEU: The Conundrum of Intentional Ambiguity

Abstract

Abstract The Russian invasion of Ukraine has had many ramifications beyond the immediate fallout of this egregious act of aggression. The blatancy of such unlawfulness at the EU’s periphery has drawn attention to a somewhat understudied provision, which, however, holds significant relevance given Ukraine’s recently awarded status as an EU candidate: The mutual assistance clause under Art 42(7) TEU. This clause will be examined by exploring its meaning and place in the European security architecture, on its own and in complementarity with Art 5 of the North Atlantic Treaty. It will be argued that both provisions of legally prescribed solidarity bear a curious and uncomfortable semblance to Schrödinger’s cat, capable of appearing as strongly worded, hard-law obligations and as undetermined intentions simultaneously. In particular, both clauses entail intentional normative ambiguity in regard to the forms of assistance to be rendered. Reflecting on how Art 42(7) TEU fits into the EU constitutional framework, it is shown that the mutual assistance clause can be read as capable of holding space for flexible and creative approaches to the legal obligations of the Member States, while as yet falling short of representing an autonomous, EU-based architecture of defence and security.