The FBI's foreign counterintelligence mission is set out in a strategy known as the National Security Threat List (NSTL). The NSTL combines two elements:
- Issues Threat List — a list of eight categories of activity that are a national security concern regardless of what foreign power or entity engages in them.
- Country Threat List — a classified list of foreign powers that pose a strategic intelligence threat to U.S. security interests. The activities of these countries are so hostile, or of such concern, that counterintelligence or counterterrorism investigations are warranted to precisely describe the nature and scope of the activities as well as to counter specific identified activities.