The theory that Europe is deeply divided over the understanding of fundamental values calls inevitably for the questioning of the core principles of the European constitutionalism and the maintenance of mutual trust between the EU Member States in the sensitive fields of criminal and asylum law. The unpleasant examples of the rule of law crisis in Poland and Hungary are now followed by the examples of Bulgaria and Romania and confirm the view that the “contagious disease” of backsliding remains a daunting challenge. How should the EU react to the effects of institutional rupture and systematic shortages in order to re-establish mutual trust and confidence in the Area of Freedom, Security and Justice? This book focuses on the balance between understanding and applying the principle of mutual trust as “blind trust” or “mutual suspicion” among the EU Member States in the new era of backsliding. In light of the recent legislative reforms in Bulgaria and Romania, the structural foundations of the EU at stake are put under the microscope. The authors provide a critical overview of the existing EU toolbox against the rule of law crisis and suggest a series of realistic improvements as regards particularly the case in Bulgaria and Romania. The book concludes with proposals of the authors as to the future steps of the EU on its difficult way towards European integration in times of a polycrisis.