Policies of territorial cooperation, including macro-regional strategies, have been a crucial component in the making of the EU space, and constitute an element of the approach adopted by the Union towards its neighbouring countries. Based on the results of in-depth interviews with 37 stakeholders from different countries and EU institutions, the article explores the potentialities and limits of the European Strategy for the Adriatic and Ionian Region (EUSAIR) to contribute to the EU enlargement towards the Western Balkan countries. Despite the limits that still hinder the full potential of the strategy, we argue that a de-centred perspective may contribute to overcoming the stalemate of the enlargement process, as long as the potentiality of a territorial approach is fully recognized and boosted.