In the first week of the Summer Programme 2019 of the Hague Academy of International Law, Professor Weller held a Special Course on "Mutual Trust: Suitable Foundation for Private International Law in Regional Integration Communities and Beyond“. In this Course, he offered a theory for Private International Law as "trust management", applied this model to groups of states with close connections amongst each other like in regional integration communities and then examined the private international law of four of such communities: the ASEAN, the CEMAC, the MERCOSUR and the EU. In the accompanying Seminar, the attendees from almost 100 countries reacted intensely to this tour d'horizon towards mutual trust. In relation to the EU's foreign trade relations Weller proposed establishing a strategy for "judicial integration" hand in hand with economic integration - so far a blind spot of the EU's external relations, as was timely demonstrated by the conclusion of the EU-MERCOSUR Trade Agreement in June 2019.

In her capacity as a Senior Research Fellow, Dr Alexia Pato contributed to establishing the Course. Dr Pato also acted as a tutor to the participants of The Hague Academy of Private International Law 2019 and as a coordinator of the Doctoral Networking Meetings. She then participated in the Centre for Studies and Research where she worked on extraterritoriality