Single Integrated Operational Plan - United Kingdom Participation

United Kingdom Participation

Although after World War II the formal military alliance between the United States and United Kingdom no longer existed, American postwar war plans required using British air bases until the United States developed ICBMs and long-range bombers. American general Carl Spaatz and Chief of the Air Staff Lord Tedder informally agreed in 1946 to US aircraft using British bases. The discussions, and the subsequent actions such as extending runways, were so secret that it is unclear whether Prime Minister Clement Attlee was aware of them. By 1948, the year of the Berlin Blockade, British leaders expected that "in a future world conflict, US and British forces will find themselves fighting side by side" although the alliance had not been formally renewed. The two countries began coordinating their plans for a Soviet attack in Europe after the Czechoslovak coup d'état of 1948, and later that year General Curtis LeMay, head of Strategic Air Command (SAC), asked Tedder to allow the basing of American atomic weapons in Britain. By the end of 1948 several British bases were atomic-capable or were close to being so, but the ability to fight an atomic war from Britain did not exist until April 1949 when "Silverplate" atomic-capable B-29 bombers began rotating through the bases, and no American atomic weapons were present in Britain until 1952.

Aware that with or without bombs the bases made Britain what Winston Churchill called a "bull's-eye" for Soviet attack, he and other British leaders repeatedly failed in learning details of American war plans, and not until 1951 did the United States formally, if vaguely, agreed to consult with Britain before using atomic weapons based there. As Tedder complained during the Berlin crisis, when war at any moment seemed possible, the defense of the west relied "on the use of a weapon about which we in fact know very little". British plans such as SPEEDWAY (December 1948), which discussed American-British-Canadian joint planning for the early part of a war over the next 18 months, likely incorporated some information informally sent by the United States, including projections on future bomb production and targets. The Chiefs of Staff Committee was dissatisfied, however, writing that "We are at a disadvantage in that ... we do not know the details of the number of atomic weapons to be used and so cannot assess with any accuracy the results that can be achieved."

The Americans preferred that the British not develop atomic weapons at all, but as that was not possible they decided that partnership was preferable to losing influence with the United Kingdom. The British sought an independent, domestic nuclear deterrent that by itself could persuade the USSR to not attack, in part because they feared that America might not be wiling to defend Europe with its nuclear missiles once the USSR could attack the United States itself, or during wartime not prioritize targets that threatened the United Kingdom. In 1950 RAF Bomber Command asked for, and received, 70 B-29s from the United States after offering to place them under the control of SAC during wartime. The bombers were becoming obsolete, however. The British never made them nuclear-capable, and the RAF refused the US's request for SAC's complete targeting control over the sophisticated British-built V bombers which began deploying in 1955. Britain's goal of an independent deterrent aimed at Soviet cities was so important that, when it offered to place the V Bombers under SACEUR authority in 1953 in exchange for American financial aid to purchase new fighters, it refused to agree to them being used in a tactical role against Soviet targets in Europe. The agreement permitted Britain to commit only nominal forces to SACEUR, and presaged future technology and targeting cooperation.

As the USAF began in 1955 helping the RAF to convert V bombers to carry American atomic weapons under Project E and hydrogen weapons under Project X, cooperation increased and the United States began sharing some war plan details. Although both nations remained reluctant to fully share their plans—as late as 1956, Britain did not have targeting information even for SAC aircraft it hosted—redundancies were eliminated by one side asking the other whether it planned to attack various targets. In February 1959 the USAF agreed to target 150 Soviet bases that threatened Britain with nuclear weapons, while V bombers would use nuclear weapons to attack Soviet air defenses before SAC arrived. The RAF retained a separate plan to attack 30 Soviet cities with hydrogen bombs. The agreement formed the basis for the ongoing nuclear-targeting cooperation between the two countries, and the different target types resembled the two nations' different priorities during their World War II strategic bombing campaign. The Anglo-American dispute during the 1956 Suez Crisis only briefly disrupted the partnership, and the desire to restore relations to their former level, and the Sputnik crisis, increased American willingness to help Britain improve its atomic weaponry. In March 1957 the United States agreed to sell 60 Thor IRBMs, in 1958 American hydrogen-weapon designs, in 1960 the Skybolt ALBM, and after its cancellation the Polaris SLBM in 1962 as replacement. Polaris was especially notable; British officials initially refused to believe the Americans' offer of state-of-the-art submarine missiles at a moderate price, and one scholar later called it "amazing".

While its contribution to SIOP was minor compared to the enormous SAC arsenal of 1,600 bombers and 800 missiles, as RAF officers who worked with the Americans rose to leadership positions their experience benefited later partnerships between the two countries. The joint targeting plan changed over time; the 1962 list for the RAF included 48 cities, six air-defense sites, and three bomber bases, and the 1963 list had 16 cities, 44 airfields and other offensive sites, 10 air-defense sites, and 28 IRBM sites. The degree of cooperation was such by the Cuban Missile Crisis that RAF officers visiting SAC headquarters in Nebraska reported being "treated just like Americans. We went all through their briefings, computers, top secret rooms and so forth". While some British officers emphasized the continuing importance of maintaining the ability to act alone with an independent deterrent if necessary, by 1962 the independent list was essentially the RAF portion of the joint plan and no active training was done. The British emphasis on retaining an independent capability, however, continued over several decades and changes in government. As the Defence Council stated in 1980,

our force has to be visibly capable of making a massive strike on its own ... We need to convince Soviet leaders that even if they thought ... the US would hold back, the British force could still inflict a blow so destructive that the penalty for aggression would have proved too high.

While current United Kingdom's nuclear forces - four Trident Vanguard class submarines - are strictly under UK national control, they had two distinct roles under the SIOP. The first was part of a UK-only retaliatory response to a nuclear attack, whether a full strategic strike, or a limited tactical strike. The second role was one in which the Royal Navy participated in the SIOP, in effect becoming an extension of the U.S. Navy's Trident submarines. This role was to be part of a NATO response to a Soviet nuclear strike. The Royal Navy's contribution to the SIOP was small. The four Vanguard submarines could strike a maximum of 512 separate targets; equivalent to 7% of the total U.S. nuclear strike capacity.