Etienne is the former Secretary General Pax Christi International (1978-2007). He is also a Research Fellow at the Berkley Center for Religion, Peace and World Affairs, Georgetown University Washington D.C. He is Board Member and Former Treasurer of European Network on Religion and Belief (Brussels), Member of European Council of Religious Leaders (Oslo, later London, now Brussels), Member of the Board of the International Peace Bureau (Berlin, Geneva, Barcelona), and Board Member of VIRA Dutch Flemish Association for International Law (Brussels).