The British nuclear stockpile,1953–2013

Abstract

Recent research has revealed new facts about the British nuclear arsenal over a 25-year period starting in 1953. This accounting and the authors’ own research support an estimate that the British produced about 1,250 nuclear warheads between 1953 and 2013. From a peak of about 500 warheads in the period between 1974 and 1981, the UK arsenal has now been reduced to some 225 weapons.

Research released over the last few years has disclosed new facts about the size, composition, and evolution of the British nuclear stockpile. ¹ In his report “British Nuclear Weapon Stockpiles, 1953–1978,” arms control historian John R. Walker (2011) drew upon official declassified documents at the National Archives at Kew, UK, to provide an accounting of the British stockpile over a 25-year period early in the Cold War.

While Walker notes that key pieces of information, including numbers of warheads used for analysis and testing, may be missing, until more elaboration is forthcoming his research will stand as the best estimate available of the types and numbers of British nuclear warheads for the years he studied. ²

In light of this new information, we now estimate that the British produced approximately 1,200 warheads of nine types from 1953 to 2013 (see Tables 1 and 2), plus an additional 45 test devices or test weapons, ³ for a total of some 1,250. This represents an increase from our earlier estimate that approximately 850 warheads were built. This new figure is equivalent to about 2 percent of the 66,500 warheads that the United States has produced (Norris and Kristensen, 2009). During the peak years of 1974 to 1981, the British stockpile included approximately 500 warheads. The peak total yield was approximately 150 megatons in 1967.

Table 1.

British nuclear warheads, 1953–2013

Table 2.

The British nuclear arsenal, 1953–2013

(continued)

From the mid-1950s, the British stockpile grew numerically and, with the introduction of the hydrogen bomb, in yield as well. Those peaks are long past as retirement of Royal Air Force (RAF) bombers and Royal Navy aircraft from nuclear missions leaves the Trident II submarine-launched ballistic missile for Vanguard nuclear submarines as the sole nuclear weapon remaining in the British stockpile. We estimate that there are approximately 225 warheads in the current stockpile (Kristensen and Norris, 2011).

The British nuclear stockpile was supplemented by a US stockpile, held in custody for British forces operating the delivery systems (see Tables 2 and 3) during the Cold War. These US weapons included gravity bombs, missile warheads, artillery shells, and atomic demolition munitions. Some of the US weapons were deployed in the United Kingdom, but most were with RAF and British Army of the Rhine units in Germany. Among the former weapons were Thor ballistic missiles, ⁴ gravity bombs for US fighter bombers at several RAF bases, ⁵ and antisubmarine warfare depth charges for US, Dutch, and British aircraft. ⁶

Table 3.

US warheads for British forces, 1958–1992

The number of US weapons stockpiled for British forces during the 1960s and 1970s was in the range of 300 to 400, dropping to between 150 and 250 in the 1980s; they were totally withdrawn by 1992. There were also US warheads for US military forces based in the United Kingdom, but these, too, have been removed and are not included in the tables. ⁷

The United States no longer supplies any warheads to British forces. In September 1991, President George H. W. Bush announced that all remaining artillery shells, Lance missile warheads, and tactical naval weapons would be returned to the United States and dismantled. On July 2, 1992, the Pentagon announced that all had been returned to US territory.

Meanwhile, Britain’s unilateral initiatives caused its stockpile to decrease by one-third, from approximately 350 to around 225.

The British nuclear stockpile went through stages similar to those that most nuclear powers have traveled: initially achieving fission bombs, then boosting them, and then creating hydrogen bombs, throughout the process miniaturizing and adapting all types of warheads to fit a variety of missiles and aircraft. What is unique in the British case is the close collaboration with the United States in research, development, and testing of warhead designs. The British government is to be commended for being transparent about a topic once shrouded in secrecy. With the disclosure of details about the UK nuclear stockpile based on declassified official documents, scholars can fill in some of the gaps in the historical record.