"Since the early 1990s, the number of international investment agreements, bilateral investment treaties, and trade agreements with clauses on foreign direct investment (FDI) has grown exponentially. These agreements between sovereign states regulate the treatment of foreign investors and capital in their territory. By early 2009, the international regime for FDI had evolved into a decentralized network of over 2600 agreements with divergent rules, but lacked any overarching multilateral framework—a stark contrast to the regime for trade. Drawing on the concept of “legalization” (or “judicialization”), i.e. the institutionalization of international relations through law, this project seeks to answer three interrelated questions. First, why have multilateral efforts to create an investment regime repeatedly failed, when bilateral agreements proliferate? Second, what explains the variation in the design of these agreements? Finally, what accounts for the evolution of the investment regime from hortatory declarations to elaborate agreements, enforceable via third-party arbitration? Existing explanations emphasize the competition between developing countries for investment. By contrast, this project hypothesizes that developed countries use international law to require developing countries to adopt and maintain a liberal economic policy. In asymmetrical bargains, major economic powers progressively ratchet up the standards for protection for their investors. The project combines formal models, case studies of the treaty programmes of the US, Japan, and the UK and their negotiations with partner countries, and statistical and quantitative network analysis. By providing a comprehensive account of the evolution of the regime, the project aims to advance our theoretical understanding and provide policy-relevant expertise in an understudied, but increasingly important issue area of international relations."