Editing UGM-27 Polaris (section)

== British Polaris ==
<!-- This section is linked from [[Campaign for Nuclear Disarmament]] -->
{{Main|Polaris (UK nuclear programme)}}
[[File:PolarisMissileIWMLondon.jpg|thumb|right|upright|British Polaris, [[Imperial War Museum]], [[London]]]]

From the early days of the Polaris program, American senators and naval officers suggested that the United Kingdom might use Polaris. In 1957 [[Chief of Naval Operations]] [[Arleigh Burke]] and [[First Sea Lord]] [[Louis Mountbatten]] began corresponding on the project. After the cancellations of the [[Blue Streak missile|Blue Streak]] and [[GAM-87 Skybolt|Skybolt]] missiles in the 1960s, under the 1962 [[Nassau Agreement]] that emerged from meetings between [[Harold Macmillan]] and [[John F. Kennedy]], the United States would supply Britain with Polaris missiles, launch tubes, ReBs, and the [[fire-control system]]s. Britain would make its own warheads and initially proposed to build five [[ballistic missile submarine]]s, later reduced to four by the incoming [[Labour Government 1964–1970|Labour government]] of [[Harold Wilson]], with 16 missiles to be carried on each boat. The Nassau Agreement also featured very specific wording. The intention of wording the agreement in this manner was to make it intentionally opaque. The sale of the Polaris was malleable in how an individual country could interpret it due to the diction choices taken in the Nassau Agreement. For the United States of America, the wording allowed for the sale to fall under the scope of [[NATO]]'s deterrence powers. On the other hand, for the British, the sale could be viewed as a solely British deterrent.<ref name=":0" /> The [[Polaris Sales Agreement]] was signed on April 6, 1963.{{r|priest2005}}

[[File:Polarisout.jpg|thumb|left|Inert training round at the National Museum of Scotland, East Fortune]]

In return, the British agreed to assign control over their Polaris missile targeting to the [[SACEUR]] (Supreme Allied Commander, Europe), with the provision that in a national emergency when unsupported by the NATO allies, the targeting, permission to fire, and firing of those Polaris missiles would reside with the British national authorities. Nevertheless, the consent of the British Prime Minister is and has always been required for the use of British nuclear weapons, including SLBMs.

The operational control of the Polaris submarines was assigned to another NATO Supreme Commander, the SACLANT (Supreme Allied Commander, Atlantic), who is based near Norfolk, Virginia, although the SACLANT routinely delegated control of the missiles to his deputy commander in the Eastern Atlantic area, COMEASTLANT, who was always a British admiral.

Polaris was the largest project in the Royal Navy's peacetime history. Although in 1964 the new Labour government considered cancelling Polaris and turning the submarines into conventionally armed hunter-killers, it continued the program as Polaris gave Britain a global nuclear capacity—perhaps [[east of Suez]]—at a cost £150 million less than that of the [[V bomber]] force. By adopting many established, American, methodologies and components Polaris was finished on time and within budget. On 15 February 1968, {{HMS|Resolution|S22|6}}, the lead ship of [[Resolution-class submarine|her class]], became the first British vessel to fire a Polaris.<ref name="priest2005">{{cite journal |last1=Priest |first1=Andrew |title=In American Hands: Britain, the United States and the Polaris Nuclear Project 1962–1968 |journal=Contemporary British History |date=September 2005 |volume=19 |issue=3 |pages=353–376 |doi=10.1080/13619460500100450 |s2cid=144941756 }}</ref> All Royal Navy [[SSBN]]s have been based at [[Faslane]], only a few miles from [[Holy Loch]]. Although one submarine of the four was always in a shipyard undergoing a refit, recent declassifications of archived files disclose that the Royal Navy deployed four boatloads of reentry vehicles and warheads, plus spare warheads for the Polaris A3T, retaining a limited ability to re-arm and put to sea the submarine that was in refit. When replaced by the Chevaline warhead, the sum total of deployed RVs and warheads was reduced to three boatloads.{{clear left}}

=== Chevaline ===
{{Main|Chevaline}}
[[File:Polaris missile launch from HMS Revenge (S27) 1986.JPEG|thumb|A Polaris missile is launched by {{HMS|Revenge|S27|6}} in 1986]]
The original U.S. Navy Polaris had not been designed to penetrate [[anti-ballistic missile]] (ABM) defenses, but the Royal Navy had to ensure that its small Polaris force operating alone, and often with only one submarine on deterrent patrol, could penetrate the ABM screen around Moscow. Britain's submarines featured the Polaris A3T missiles, a modification to the model of the Polaris used by the U.S. from 1968 to 1972. Similar concerns were present in the U.S. as well, resulting in a new American defense program.<ref>{{cite journal |last1=Parr |first1=Helen |title=The British Decision to Upgrade Polaris, 1970–4 |journal=Contemporary European History |date=May 2013 |volume=22 |issue=2 |pages=253–274 |id={{ProQuest|1323206104}} |doi=10.1017/S0960777313000076 |s2cid=163187309 }}</ref>

The program became known as Antelope, and its purpose was to alter the Polaris. Various aspects of the Polaris, such as increasing deployment efficiency and creating ways to improve the penetrative power were specific items considered in the tests conducted during the Antelope program. The British's uncertainty with their missiles led to the examination of the Antelope program. The assessments of Antelope occurred at [[Aldermaston]]. Evidence from the evaluation of Antelope led to the British decision to undertake their program following that of the United States.<ref name=":0" />

The result was a programme called ''[[Chevaline]]'' that added multiple decoys, [[Chaff (radar countermeasure)|chaff]], and other defensive [[countermeasure]]s. Its existence was only revealed in 1980, partly because of the cost overruns of the project, which had almost quadrupled the original estimate given when the project was finally approved in January 1975. The program also ran into trouble when dealing with the British [[Labour Party (UK)|Labour Party]]. Their Chief Scientific Adviser, [[Solly Zuckerman, Baron Zuckerman|Solly Zuckerman]], believed that Britain no longer needed new designs for nuclear weapons and no more nuclear warhead tests would be necessary. Though the Labour Party provided a clear platform on nuclear weapons, the Chevaline program found supporters. One such individual who supported modification to the Polaris was the Secretary of State for Defence, [[Denis Healey]].<ref name=":0">{{cite journal |last1=Spinardi |first1=Graham |title=Aldermaston and British Nuclear Weapons Development: Testing the 'Zuckerman Thesis' |journal=Social Studies of Science |date=August 1997 |volume=27 |issue=4 |pages=547–582 |doi=10.1177/030631297027004001 |jstor=285558 |s2cid=108446840 }}</ref>

Despite the approval of the program, the expenses caused hurdles that augmented the time it took for the system to come to fruition. The cost of the project led to Britain's disbanding the program in 1977. The system became operational in mid-1982 on {{HMS|Renown|S26|6}}, and the last British [[SSBN]] submarine was equipped with it in mid-1987.<ref>[http://nuclearweaponarchive.org//Uk/UKArsenalDev.html History of the British Nuclear Arsenal], Nuclear Weapons Archive website</ref> Chevaline was withdrawn from service in 1996.

Though Britain adopted the Antelope program methods, no input on the design came from the United States. Aldermaston was solely responsible for the Chevaline warheads.

=== Replacement ===
The British did not ask to extend the Polaris Sales Agreement to cover the Polaris successor [[UGM-73 Poseidon|Poseidon]] due to its cost.{{r|priest2005}} The [[Ministry of Defence (United Kingdom)|Ministry of Defence]] upgraded its nuclear missiles to the longer-ranged [[Trident (missile)|Trident]] after much political wrangling within the Callaghan [[Labour Party (UK)|Labour Party]] government over its cost and whether it was necessary. The outgoing Prime Minister [[James Callaghan]] made his government's papers on Trident available to [[Margaret Thatcher]]'s new incoming [[Conservative Party (UK)|Conservative Party]] government, which took the decision to acquire the [[UGM-96 Trident I|Trident C4]] missile.

A subsequent decision to upgrade the missile purchase to the even larger, longer-ranged Trident D5 missile was possibly taken to ensure that there was missile commonality between the [[U.S. Navy]] and the [[Royal Navy]], which was considerably important when the Royal Navy Trident submarines were also to use the [[Naval Submarine Base Kings Bay]].

Even though the U.S. Navy initially deployed the Trident C4 missile in the original set of its ''Ohio''-class submarines, it was always planned to upgrade all of these submarines to the larger and longer-ranged Trident D5 missile—and that eventually, all of the C4 missiles would be eliminated from the U.S. Navy. This change-over has been completely carried out, and no Trident C4 missiles remain in service.

The Polaris missile remained in Royal Navy service long after it had been completely retired and scrapped by the U.S. Navy in 1980–1981. Consequently, many spare parts and repair facilities for the Polaris that were located in the U.S. ceased to be available (such as at [[Lockheed Martin|Lockheed]], which had moved on first to the Poseidon and then to the Trident missile).