The thesis conducts a review of the US Alien Tort Statute (ATS) to determine how it may be used to improve the prospects of international law enforcement in national courts, particularly with regard to international human rights law. Analysis follows case law under the statute and deals with a series of discreet issues that have arisen in US courts. An argument is made in earlier chapters that the ATS may be used to improve the prospects of international law enforcement if US judges voluntarily adopt legal standards issued by international courts and tribunals. Later chapters examine case law from the US Supreme Court to assess how the statute may improve international law enforcement in the future. Particular areas of interest are the extraterritorial application of US law, corporate liability for international law violations, how to manage the foreign policy implications of the statute, and the possibility of a similar legislative development in the UK. The thesis concludes that the ATS may be used to improve the prospects of international law enforcement in key areas, which are identified by an examination of case law.