Editing Intercontinental ballistic missile (section)

=== Cold War ===
After World War II, the Americans and the Soviets started rocket research programs based on the V-2 and other German wartime designs. Each branch of the US military started its own programs, leading to considerable duplication of effort. In the Soviet Union, rocket research was centrally organized although several teams worked on different designs.

The US initiated ICBM research in 1946 with the [[RTV-A-2 Hiroc]] project. This was a three-stage effort with the ICBM development not starting until the third stage. However, funding was cut in 1948 after only three partially successful launches of the second stage design, that was used to test variations of the V-2 design. With overwhelming air superiority and truly intercontinental bombers, the newly formed [[US Air Force]] did not take the problem of ICBM development seriously. Things changed in 1953 with the Soviet testing of [[Joe 4|their first]] [[thermonuclear weapon]], but it was not until 1954 that the [[SM-65 Atlas|Atlas missile]] program was given the highest national priority. The Atlas A first flew on 11 June 1957; the flight lasted only about 24 seconds before the rocket exploded. The first successful flight of an Atlas missile to full range occurred 28 November 1958.<ref>{{cite web |url=http://www.century-of-flight.net/Aviation%20history/space/Atlas.htm |title=Atlas |publisher=Century of Flight |work=The Exploration of Space |access-date=2012-12-14 |archive-url=https://web.archive.org/web/20111011002749/http://century-of-flight.net/Aviation%20history/space/Atlas.htm |archive-date=11 October 2011 |url-status=live }}</ref> The first armed version of the Atlas, the Atlas D, was declared operational in January 1959 at Vandenberg, although it had not yet flown. The first test flight was carried out on 9 July 1959,<ref>{{cite web|url=http://www.missilethreat.com/missilesoftheworld/id.15/missile_detail.asp |title=Atlas D |publisher=Missile Threat |access-date=2012-04-19  |archive-url=https://web.archive.org/web/20120210160153/http://www.missilethreat.com/missilesoftheworld/id.15/missile_detail.asp |archive-date=10 February 2012 }}</ref> and the missile was accepted for service on 1 September. The [[HGM-25A Titan I|Titan I]] was another US multistage ICBM, with a successful launch February 5, 1959, with Titan I A3. Unlike the Atlas, the Titan I was a two-stage missile, rather than three. The Titan was larger, yet lighter, than the Atlas. Due to the improvements in engine technology and guidance systems the Titan I overtook the Atlas.<ref>{{cite web |title=Air Force Space & Missile Museum |url=https://afspacemuseum.org/artifacts/titan-i/ |access-date=29 June 2022 |archive-date=21 October 2021 |archive-url=https://web.archive.org/web/20211021074042/https://afspacemuseum.org/artifacts/titan-i/  }}</ref>
[[File:Atlas-B ICBM.jpg|thumb|upright|An [[SM-65 Atlas]], the first US ICBM, first launched in 1957]]

In the Soviet Union, early development was focused on missiles able to attack European targets. That changed in 1953, when [[Sergei Korolev]] was directed to start development of a true ICBM able to deliver newly developed hydrogen bombs. Given steady funding throughout, the [[R-7 Semyorka|R-7]] developed with some speed. The first launch took place on 15 May 1957 and led to an unintended crash {{convert|400|km|abbr=on}} from the site. The first successful test followed on 21 August 1957; the R-7 flew over {{convert|6000|km|abbr=on}} and became the world's first ICBM.<ref name=FirstICBM>{{cite book |last1=Siddiqi |first1=Asif |title=Challenge to Apollo: the Soviet Union and the space race, 1945–1974 |date=2000 |publisher=National Aeronautics and Space Administration, NASA History Div |pages=160–161 |url=https://history.nasa.gov/SP-4408pt1.pdf |access-date=17 August 2023}}</ref> The first strategic-missile unit became operational on 9 February 1959 at [[Plesetsk Cosmodrome|Plesetsk]] in north-west Russia.<ref>{{cite web|url=http://www.eucom.mil/article/23076/this-week-in-eucom-history-february-6-12-1959 |title=This Week in EUCOM History: February 6–12, 1959 |date=6 February 2012 |publisher=[[EUCOM]] |access-date=2012-02-08  |archive-url=https://web.archive.org/web/20120921003453/http://www.eucom.mil/article/23076/this-week-in-eucom-history-february-6-12-1959 |archive-date=21 September 2012}}</ref>

It was the same [[R-7 Semyorka|R-7]] [[launch vehicle]] that placed the first artificial satellite in space, [[Sputnik 1|Sputnik]], on 4 October 1957. The first [[human spaceflight]] in history was accomplished on a derivative of R-7, [[Vostok (rocket family)|Vostok]], on [[Cosmonautics Day|12 April 1961]], by [[Soviet Union|Soviet]] [[cosmonaut]] [[Yuri Gagarin]]. A heavily modernized version of the R-7 is still used as the [[launch vehicle]] for the Soviet/Russian [[Soyuz (spacecraft)|Soyuz spacecraft]], marking more than 60 years of operational history of [[Sergei Korolyov]]'s original rocket design.

The R-7 and Atlas each required a large launch facility, making them vulnerable to attack, and could not be kept in a ready state. Failure rates were very high throughout the early years of ICBM technology. Human spaceflight programs ([[Vostok programme|Vostok]], [[Project Mercury|Mercury]], [[Voskhod programme|Voskhod]], [[Project Gemini|Gemini]], etc.) served as a highly visible means of demonstrating confidence in reliability, with successes translating directly to national defense implications. The US was well behind the Soviets in the [[Space Race]] and so US President [[John F. Kennedy]] increased the stakes with the [[Apollo program]], which used [[Saturn (rocket family)|Saturn rocket]] technology that had been funded by President [[Dwight D. Eisenhower]].

[[File:USAF ICBM and NASA Launch Vehicle Flight Test Successes and Failures (highlighted).png|thumb|upright=1.5|1965 graph of USAF [[SM-65 Atlas|Atlas]] and Titan ICBM launches, cumulative by month with failures highlighted (pink), showing how [[NASA]]'s use of ICBM boosters for Projects Mercury and Gemini (blue) served as a visible demonstration of reliability at a time when failure rates had been substantial.]]

These early ICBMs also formed the basis of many space launch systems. Examples include [[R-7 (rocket family)|R-7]], [[Atlas (rocket family)|Atlas]], [[Redstone (rocket family)|Redstone]], [[Titan (rocket family)|Titan]], and [[Proton (rocket)|Proton]], which was derived from the earlier ICBMs but never deployed as an ICBM. The Eisenhower administration supported the development of solid-fueled missiles such as the [[LGM-30 Minuteman]], [[UGM-27 Polaris|Polaris]] and [[GAM-87 Skybolt|Skybolt]]. Modern ICBMs tend to be smaller than their ancestors, due to increased accuracy and smaller and lighter warheads, and use solid fuels, making them less useful as orbital launch vehicles.

The Western view of the deployment of these systems was governed by the strategic theory of [[mutual assured destruction]]. In the 1950s and 1960s, development began on [[anti-ballistic missile]] systems by both the Americans and Soviets. Such systems were restricted by the 1972 [[Anti-Ballistic Missile Treaty]]. The first successful ABM test was conducted by the Soviets in 1961, which later deployed a fully operational system defending Moscow in the 1970s (see [[Anti-ballistic missile#Moscow ABM system|Moscow ABM system]]).

The 1972 [[Strategic Arms Limitation Talks|SALT]] treaty froze the number of ICBM launchers of both the Americans and the Soviets at existing levels and allowed new [[submarine]]-based [[Submarine-launched ballistic missile|SLBM]] launchers only if an equal number of land-based ICBM launchers were dismantled. Subsequent talks, called SALT II, were held from 1972 to 1979 and actually reduced the number of nuclear warheads held by the US and Soviets. SALT II was never ratified by the [[US Senate]], but its terms were honored by both sides until 1986, when the Reagan administration "withdrew" after it had accused the Soviets of violating the pact.

In the 1980s, President [[Ronald Reagan]] launched the [[Strategic Defense Initiative]] as well as the [[LGM-118 Peacekeeper|MX]] and [[MGM-134 Midgetman|Midgetman]] ICBM programs.

China developed a minimal independent nuclear deterrent entering its own cold war after an [[Sino-Soviet split|ideological split]] with the Soviet Union beginning in the early 1960s. After first testing a domestic built [[nuclear weapon]] in 1964, it went on to develop various warheads and missiles. Beginning in the early 1970s, the liquid fuelled [[DF-5]] ICBM was developed and used as a satellite launch vehicle in 1975. The DF-5, with a range of {{convert|10000|to|12000|km|abbr=on}}—long enough to strike the Western United States and the Soviet Union—was silo deployed, with the first pair in service by 1981 and possibly twenty missiles in service by the late 1990s.<ref name="fas.org">{{cite web |url=https://www.fas.org/nuke/guide/china/icbm/df-5.htm |title=DF-5 |publisher=[[Federation of American Scientists]] |work=Weapons of Mass Destruction / WMD Around the World |access-date=2012-12-14 |archive-url=https://web.archive.org/web/20120416025855/http://www.fas.org/nuke/guide/china/icbm/df-5.htm |archive-date=16 April 2012 |url-status=live }}</ref> China also deployed the [[JL-1]] [[Medium-range ballistic missile]] with a reach of {{convert|1700|km}} aboard the ultimately unsuccessful [[Type 092 submarine]].<ref>{{cite web |url=https://www.fas.org/nuke/guide/china/slbm/type_92.htm |title=Type 92 Xia |publisher=[[Federation of American Scientists]] |work=Weapons of Mass Destruction Around the World |access-date=2012-12-14 |archive-url=https://web.archive.org/web/20120219175846/http://www.fas.org/nuke/guide/china/slbm/type_92.htm |archive-date=19 February 2012 |url-status=live }}</ref>