The Treaty of Amsterdam has introduced important changes into the constitution of the European Union, for example, in the fields of internal and external affairs and employment policy, which will impact upon the future of the Union. Also of considerable importance is the new option to establish closer co-operation between a group of Member States, as well as certain institutional modifications. Particular attention is paid to areas of the Treaty of Amsterdam which are unclear or apparently deficient. All of these topics are of greatest importance within the course of the ongoing thematic debate, not the least on future EU-enlargement. The book is addressed to experts and anyone interested in European affairs. The Treaty of Amsterdam has introduced important changes which will impact upon the future of the European Union. The entry into force of the Treaty will result in some major changes, for example, in the fields of internal and external affairs and employment policy. Also of potentially considerable importance is the new option to establish closer co-operation between a group of Member States, as well as certain institutional modifications. The new Treaty is presented with reference to the agenda of the most recent Intergovernmental Conference. Particular attention is paid to areas of the Treaty of Amsterdam which are unclear or apparently deficient. The book is addressed to experts and anyone interested in European affairs.