United States nuclear surety

It is a policy of the U.S. government that its nuclear weapons, production facilities, National Command Authority and other command and control, and delivery systems will combine into a comprehensive system of nuclear surety "that make them safe, secure, and under positive control. Surety encompasses design features, material, personnel, and procedures."

Positive Control
The positive control architecture begins by placing the command authority for the use and critical manipulations at the highest policy level of the government, but, even there, enforcing the two-man rule. No action affecting the safety or use of nuclear weapons is ever left to one person, so the National Command Authority, the civilian authority with ultimate responsibility, is made up of both the President of the United States and the U.S. Secretary of Defense, or their succcessors.

Two-person control continues through all command and control levels, from high military levels down to weapon maintenance and firing crews. Control has not always been perfect; in 2009, six nuclear missiles were, through a combination of inattention, inadequate procedures, and failure to carry out inspections, were transferred unknowingly from one U.S. base to another.

Operational weapons surety
Weapons themselves have a growing number of internal and colocated safeguards against accident and misuse.