This policy brief examines options for improving international regulation of private military and security companies (PMSCs). In late 2008, seventeen states, including the US, UK, China, Iraq, and Afghanistan, endorsed the  Montreux Document, providing guidance to states in regulating PMSCs. But there is a need to do more to provide increased guidance to industry and to ensure standards are enforced. There are positive signs that the Obama administration will step up efforts to improve regulation, both domestically and internationally. And there are signs that other states, such as Switzerland, the UK, and Canada, are also willing to act. But a roadmap for effective international regulation is needed. Domestic regulation is not enough, because the industry is increasingly global. Even many of the PMSCs employed by the US government are incorporated offshore, and recruit third-country nationals that they then deploy overseas without their ever having entered US jurisdiction. What is needed is a global framework to assist states in regulating this industry.