Introduction

As a young German Visiting Researcher at Havard Law School in 1994–5, Detlev Vagts' class on Transnational Legal Problems opened up a new perspective on international law for me: pragmatic and pluralist rather than doctrinal and separated into public law, private law and criminal law. In addition, the Jubilee impressed me with his keen interest in German law and culture. Thus, while being forced to rethink the traditional German approach to all things legal, Detlev made the young German student feel at home both intellectually and personally. The following contribution to his Festschrift attempts to follow Detlev's example.

For one of the fathers of the transnational law approach, it will hardly come as a surprise that both the German and the US legal orders are faced with an increasing fragmentation of the legal landscape, in which domestic law cannot but pay attention to European, international and, at times, foreign law. However, both are also concerned with democratic legitimacy and the preservation of domestic prerogatives of parliaments and courts. In Europe, the matter becomes even more complicated. While European law is not ‘domestic’ in character, but has been established by a treaty between States, its law is ‘supranational’, e.g. directly applicable to individuals in its Member States. Thus, the European legal order faces an additional difficulty when faced with international decisions: it must first decide ‘on which side it is’, in other words, whether it regards its own legal order, in a monist perspective, as part of international law, or as a separate legal order that faces international law the same way as a domestic legal order.