1. 1Associate Professor of European Union Law, University of Teramo; Member of the Committee on International Law concerning Foreign Direct Investment of the International Law Association. The present article is based on a paper circulated at the Fourth Public Conference of the British Institute of International and Comparative Law's Investment Treaty Forum on "Nationality and Investment Treaty Claims", held in London on 6 May 2005. The author may be contacted at pacconci@tiscali.it.