National laws sometimes reach outside the country that adopted them, and laws in these cases produce extraterritorial effects. But regardless of whether national laws do or do not have extraterritorial effects, they sometimes require enforcement abroad. The need for extraterritorial enforcement arises when a defendant and its assets are located outside the country of the court or agency that wants to enforce the laws. This situation may occur frequently on the Internet because the Internet makes it easy for people to strategically locate their assets and conduct their affairs in different countries in an attempt to avoid the enforcement power of certain jurisdictions. This chapter discusses the extraterritorial enforcement of national laws on the Internet and considers whether extraterritorial enforcement can be improved. Improvements might be desirable for several reasons. For example, improvements in enforceability would bring clarity to legislative debates on substantive issues and contribute to better substantive policy choices not clouded with concerns about the feasibility of enforcement. Countries have already developed alternative enforcement mechanisms, such as enforcement through the assistance of Internet service providers and payment processors, but these mechanisms generate their own problems and cannot fully replace direct enforcement. The chapter begins by discussing limits on the ubiquity of activities on the Internet and the lack of uniformity in conducting commercial activity on the Internet. Geoblocking and other market partitioning tools are among the means that actors on the Internet employ to limit the territorial reach of their activities on the Internet. The chapter discusses differences between the point-of-source and point-of-consumption principles and rationales that lead legislators to choose between the two principles when drafting legislation. The chapter further explains the limitations on a country’s enforcement capacity and the extent to which a country may rely on other countries for enforcement assistance. The ability of countries to enforce by themselves, and to assist other countries with enforcement, is subject to certain supranational limitations on extraterritorial enforcement, which the chapter also explores. The chapter concludes by making suggestions for improvements in extraterritorial enforcement of national laws: for example, it seems reasonable to use the same vehicle – the Internet – that generates the disputes to facilitate the resolution of those disputes, particularly when the disputes necessitate extraterritorial enforcement.