The British Snake in the US Nuclear Weapons Program
March 10, 2012 • 10:30AM

The U.S. atomic bombs that were dropped on Japan in 1945 were built with a great deal of collaboration from the British government and British scientists. The British got involved in the American program when their own program to build a bomb became unviable under the conditions prevailing in wartime Britain. Their intention to remain a nuclear power was encapsulated in a statement attributed to Foreign Minister Ernest Bevin in 1946: "We have got to have this thing over here, whatever it costs... we have got to have a bloody Union Jack on top of it!" However, the U.S. Congress slammed the door shut to further cooperation by passage of the 1946 McMahon Act, which prohibited sharing of information and technology of atomic weapons with foreign powers. The British motivation behind seeking the 1958 Mutual Defense Agreement, which re-opened that door, was so that they could once again gain access to American nuclear weapons engineering capability, without which there would be no British nuclear "deterrent."

Just how much access the British have had to the U.S. nuclear weapons program became public knowledge last year, when the Ministry of Defense disclosed the number of visits that personnel from the Atomic Weapons Establishment at Aldermaston had made to nuclear weapons and other facilities in the U.S. under the terms of the 1958 agreement. There were 900 visits in 2007, 876 in 2008 and 787 in 2009 (the reason for the decline is not explained). The facilities visited most often were Los Alamos National Laboratory, with 575 visits over the three years; Sandia National Laboratory, with 555 visits; and Lawrence Livermore, with 463 visits. There were also 105 visits to the Nevada Test Site. Sandia Labs reported, in its own newsletter in April 2011, progress in the development of upgraded W76 warheads, along with the Mk.4A re-entry vehicle, which are to be integrated onto Britain's submarine launched ballistic missiles.

Given this level of access and collaboration, there probably isn't much about the U.S. nuclear weapons enterprise that the British don't know.