What makes the relationship between Switzerland and the EU so challenging? For both parties, mutual relations are of crucial importance, not least economically. As a result of the Swiss voters’ rejection of the European Economic Area 30 years ago, there is at present a large number of agreements that provide for Switzerland's partial participation in the EU's internal market as well as other matters. At the same time, there has now for more than a decade been an increasing degree of institutional and legal uncertainty. The present volume offers an inventory of different sides of this special relationship, which is interesting also in a comparative context.