Nuclear security

Declassified: US nuclear weapons at sea during the Cold War

In February 2015, the US Defense Department declassified numbers on how many nuclear weapons the United States deployed at sea between 1953 and 1991 (US Defense Department 2015). The declassification shows the total number of nuclear weapons that were on board a variety of naval vessels – including aircraft carriers, cruisers, destroyers, frigates, attack submarines, and ballistic missile submarines – at the end of each fiscal year in the Atlantic and Pacific oceans and the Mediterranean Sea (see Table 1). We last wrote about US nuclear weapons afloat during that period in a 1999 Nuclear Notebook column (Norris, Arkin, and Burr, 1999). It used information from an important Pentagon study released under the Freedom of Information Act. However, our estimates made at the time from sanitized graphs were approximate. With this new declassification, we now have hard numbers.