A harmonized international regime that enhances biosecurity is needed to reduce the risk of bioterrorism. Like other security regimes, this will entail mutually reinforcing strands, which need to include: enactment of legally binding control of access to dangerous pathogens, transparency for sanctioned biodefense programs, technology transfer and assistance to developing countries to jointly advance biosafety and biosecurity, global awareness of the dual-use dilemma and the potential misuse of science by terrorists, and development of a global ethic of compliance. To work, this effort must be undertaken collectively, utilizing the international and regional institutions that already have a role to play in providing safety and security. Most notably, it must grow in a top-down manner from the Biological Weapons Convention accord, in which States Parties have agreed to ban the development of biological weapons, and in a bottom-up manner from the scientific and health communities, which are engaged in the research and public health efforts that must be protected against misuse-especially involving the World Health Organization.