The United States is releasing newly declassified information on the U.S. nuclear weapons stockpile to update the information released in May 2010. Increasing the transparency of global nuclear stockpiles is important to nonproliferation efforts, including commitments under the Nuclear Nonproliferation Treaty, and the pursuit of further reductions that cover all nuclear weapons: deployed and non-deployed, strategic and non-strategic.

Stockpile. As of September 2013, the U.S. stockpile of nuclear warheads consisted of 4,804 warheads. This number represents an 85 percent reduction in the stockpile from its maximum (31,255) at the end of fiscal year 1967, and a 78 percent reduction from its level (22,217) when the Berlin Wall fell in late 1989. The below figure shows the U.S. nuclear stockpile from 1945 through September 30, 2013.

Warhead Dismantlement. From fiscal years 1994 through 2013, the United States dismantled 9,952 nuclear warheads. Since September 30, 2009, the United States has dismantled 1,204 nuclear warheads. Several thousand additional nuclear weapons are currently retired and awaiting dismantlement.

Non-Strategic Nuclear Weapons. The number of U.S. non-strategic nuclear weapons has declined by approximately 90 percent since September 30, 1991.

Fiscal Years Includes active and inactive warheads. Several thousand additional nuclear warheads are retired and awaiting dismantlement.

Definitions

The nuclear stockpile includes both active and inactive warheads. Active warheads include strategic and non-strategic weapons maintained in an operational, ready-for-use configuration, warheads that must be ready for possible deployment within a short timeframe, and logistics spares. They have tritium bottles and other Limited Life Components installed. Inactive warheads are maintained at a depot in a non-operational status, and have their tritium bottles removed.

A retired warhead is removed from its delivery platform, is not functional, and is not considered part of the nuclear stockpile. Weapons awaiting dismantlement constitute a significant fraction of the total warhead population and will increase as the New START Treaty is implemented and as unneeded warheads are retired. A dismantled warhead is a warhead reduced to its component parts.