He has held several high-ranking official positions, such as deputy chief of the Cabinet of the Belgian Minister of DefenceGuy Coeme and deputy chief of the Cabinet of the Minister of Foreign AffairsWilly Claes and deputy chief of the Cabinet of the Minister of Foreign Affairs Willy Claes where he was in charge for the contacts with the USA regarding the Rwandan genocide. From 2002 until 2009 he served as Director of the "Security & Global Governance" program at the Egmont Institute in Brussels. Coolsaet was later active in the Cabinets of other socialist ministres such as Frank Vandenbroucke and Erik Derycke.
Publications
Coolsaet's research focuses on Belgian foreign policy, terrorism and radicalisation, security studies, and international relations. In 1998, he published a study on the history of Belgian foreign policy. The latest revised edition, released in September 2014, pursues this history until 2014. Two other studies on Belgian foreign policy deal with Dutch-Belgian bilateral relations since 1945 and with the history of the Ministry of Foreign Affairs: Les Affaires étrangères au service de l’Etat belge, de 1830 à nos jours and, in Dutch, Buitenlandse Zaken in België. Geschiedenis van een ministerie, zijn diplomaten en zijn consuls van 1830 tot vandaag, with Vincent Dujardin and late Claude Roosens. He has been coordinating research on terrorism and radicalisation, which has resulted in several publications. Jihadi Terrorism and the Radicalisation Challenge. European and American Experiences was published by Ashgate in 2011. This volume was included in the 2012 "Top 150 Books on Terrorism and Counterterrorism", established by the academic journalPerspectives on Terrorism. His analysis on the impact of 9/11 on Europe was published in 2013 in a volume edited by Mohammed Ayoob and Etga Ugur of Michigan State University. His most recent studies on radicalisation and terrorism have all been released by the Egmont Institute: Returnees – Who are they, why are they coming back and how should we deal with them ? Assessing policies on returning Foreign Terrorist Fighters in Belgium, Germany and the Netherlands ; Anticipating the post-Daesh landscape ; ‘All Radicalisation is Local’. The genesis and drawbacks of an elusive concept ; Facing the fourth foreign fighters wave. What drives Europeans to Syria, and to Islamic State? Insights from the Belgian case. Coolsaet has also written extensively on international relations, mostly in Dutch. His Macht en Waarden in de Wereldpolitiek provides for a yearly overview of major trends in global politics. A 2008 publication, De geschiedenis van de wereld van morgen, analyzed long-term change patterns in international relations. Upon publication in February 2008, this book appeared on the Belgian bookshops' bestseller list for several months.
