Size of U.S. Nuclear Arsenal Remains Classified

01.08.15 | 2 min read | Text by Steven Aftergood

The U.S. government will not categorically declassify the number of weapons in the U.S. nuclear arsenal once and for all, but it will consider declassification of the size of the prior year’s arsenal on a case by case basis, the Department of Energy said last week.

In May 2010, the Obama Administration declassified the fact that there were 5,113 warheads in the U.S. arsenal as of September 2009. It was the first time in the nuclear age that the current size of the U.S. arsenal (or any nation’s arsenal) was officially disclosed.

Last year, the numbers were updated through September 2013, when there were a reported 4,804 warheads.

Why not make such disclosures routinely and as a matter of course? Last May, the Federation of American Scientists presented a proposal to that effect to the joint DOE/DOD Formerly Restricted Data (FRD) Declassification Working Group (DWG). Officials rejected the idea.

“The FRD DWG has determined that it cannot agree to your request at this time,” wrote Andrew P. Weston-Dawkes, the Director of the DOE Office of Classification in a December 30, 2014 letter.

Instead, “any public request for stockpile and dismantlement numbers beyond September 30, 2013, should be made as a separate declassification request for the prior fiscal year,” he wrote. “Public requests for this information will not be considered for future out-years.”

Accordingly, we submitted a request this week for declassification of the stockpile and dismantlement figures as of the end of fiscal year 2014 (i.e., September 30, 2014).

“As a matter of principle, information should remain classified only when doing so serves a valid and compelling national security purpose. We believe that continued classification of the size of the FY 2014 nuclear stockpile does not meet that criterion,” the FAS request said.

In the absence of officially declassified stockpile numbers, it is nevertheless possible for diligent students of the subject to reliably assess the size of the nuclear arsenal.

In February 2009, prior to the declassification of the 2009 stockpile figure of 5,113 warheads, Hans Kristensen and Robert S. Norris of FAS estimated the number to be 5,200 warheads, an impressively close approximation. The estimate was published in their Nuclear Notebook column, which monitors nuclear arsenals worldwide based on open sources, and which regularly appears in the Bulletin of the Atomic Scientists.

Norris and Kristensen reflect on the origins and the purposes of the Nuclear Notebook in the latest issue of the Bulletin of the Atomic Scientists. See “Counting Nuclear Warheads in the Public Interest,” January 2015.