The contributions of the following organizations and offices are gratefully acknowledged:

• Defense Threat Reduction Agency
• Joint Atomic Information Exchange Group
• Joint Staff
• National Nuclear Security Administration Defense Programs
• NNSA Office of Nuclear Counterterrorism
• Office of the Deputy Under Secretary of Energy for Counterterrorism
• Office of the Secretary of Defense/Intelligence
• Office of the Secretary of Defense/Policy
• Science Applications International Corporation
• Toeroek and Associates
• United Kingdom Ministry of Defence
• United States Strategic Command