The unprecedented expansion and growing complexity of international economic relations over the last decades have significantly affected the scope and nature of existing international law. Numerous bilateral investment trade agreements (BITs), and multilateral instruments such as the GATT, NAFTA and the 1994 Energy Charter Treaty (ECT) have added to the increasing body of international trade and investment law. From the perspective of general international law, this emerging lex mercatoria is a force to be reckoned with. It is the ‘interface of international business/commercial law with public international law has never been an easy exercise. An issue that perhaps best identifies the complexity of such an endeavour relates to the responsibility of the State for non-State actors in the area of commercial transactions. While this issue has yet to be clarified fully in international law, it is one that is of particular importance to international economic relations.