Free trade agreements between developed countries now frequently contain provisions on investor protection, but the resolution of disputes remains problematic. Chapter 11 of the North American Free Trade Agreement (NAFTA) allows investors to bring direct claims against a host state before an international tribunal without exhausting domestic remedies. This has resulted in a number of claims against the United States by Canadian investors and against Canada by U.S.investors. Chapter 11 of the Australia-United States Free Trade Agreement (AUSFTA) does not permit direct claims, relying instead on a state-to-state dispute resolution mechanism. This Article reviews the evolution of investment-dispute resolution from diplomatic protection to NAFT...