Mutual Trust without EU Membership: Challenging the Foundations of the Principle of Mutual Trust

EU law is underpinned by the fundamental premise that each member state respects EU law and provides equivalent and effective fundamental rights protection. In Opinion 1/17 , the Court of Justice held that the principle of mutual trust is not applicable between member states and third countries. Yet, from its case law it appears that the apparently closed circle of trust may nonetheless be opened up to some closely associated third countries, although the foundations underpinning mutual trust may not (fully) exist with respect to those countries. This article examines how this observation may inform our understanding of the principle of mutual trust within the EU and raises the question of whether the current conception of mutual trust can be maintained.