The rapidly growing number of investors' disputes with states and the approach of arbitral tribunals, perceived by some, whether rightly or not, as being too investor-friendly, underlie a contentious debate about the need to strike a more effective balance between investors' rights under international investment agreements (IIAs) and the right of states to pursue legitimate regulation in the public interest. In this regard the European Union, with the exclusive external competence in foreign direct investment vested in it under the Lisbon Treaty, is emerging as the leader and driving force in the future development of international investment law. This book examines the competence of the EU to conclude investment treaties in the light of the investment protection rules of IIAs, explores how far the EU regime for cross-border investment and investors' rights under IIAs can be considered comparable, and brings about an extensive analysis of existing agreements of Member States and their compatibility with EU law, with detailed investigation of how the potentially conflicting obligations of Member States under the two regimes can be reconciled. The book covers such elements of the debate as the following:   'standards of treatment' under IIAs; investment-related provisions of EU law; dispute settlement mechanisms and the conduct of investment disputes; how recent controversies over bilateral investment treaties (BITs) shape emerging EU international investment policy; effect of political and institutional interests; transitional arrangements for BITs between Member States and third countries established by Regulation 1219/2012; CJEU decisions concerning BITs concluded between EU Member States and third countries; significant arbitral awards involving intra-EU BITs; allocation of international responsibility for breaches of investors' rights; intra-EU dimension of the Energy Charter Treaty (ECT); possibilities for review of arbitral awards by courts of Member States; desirability of international protection of foreign investment in developed countries; and role of the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention) The author provides a number of well-grounded recommendations, taking into account throughout the legitimate interests and expectations of individual investors. As an invaluable commentary on developments related to the interplay between international investment law and EU law, and a guide to ameliorating the tensions and controversies surrounding this relationship, this book will appeal to a wide variety of readers. The questions dealt with are faced not only by negotiators and others involved in policymaking in the area of foreign investment, but also by specialists in international investment law, investment arbitration, EU international relations law, and anyone involved in cross-border law, as well as others who encounter these questions in the course of their professional or academic activities.