The climate surrounding foreign investment law is one of controversy and change, and with implications for human rights and environmental protection, foreign investment law has gained widespread public attention and visibility. This fully updated edition of Sornarajah's classic text offers thought-provoking analysis of the law in historical, political and economic contexts, capturing leading trends and charting the possible course of future developments. It takes into account the newer types of treaties that establish a regulatory space for states and moves away from inflexible investment protection, exploring the newly created defences relating to environment, human rights, indigenous rights and other areas ending the fragmentation of the law. It looks at the current debates on legitimacy of the system and current efforts at reform. Suitable for postgraduate and undergraduate students, The International Law on Foreign Investment is essential reading for anyone specialising in the law of foreign investments.