Soviet Union and weapons of mass destruction
The Soviet Union had, by 1991, the world's largest stockpiles of nuclear, biological, and chemical weapons. It carried out its first nuclear test in 1949 and its first multi-stage thermonuclear test in 1955. It was one of the five nuclear-weapon states of the Non-Proliferation Treaty, and its biological warfare program was in violation of its ratification of the Biological Weapons Convention. These programs were inherited primarily by Russia.
In 1991, the Soviet Union possessed approximately 29,000 nuclear warheads. The Soviet Armed Forces operated a nuclear triad that deployed over 10,000 strategic nuclear weapons: 6,280 warheads assigned to the Strategic Rocket Forces' 1,334 intercontinental ballistic missiles, 3,626 warheads to the Soviet Navy's 914 submarine-launched ballistic missiles, and 974 cruise missiles and bombs to Long Range Aviation's 106 Tu-95MS and Tu-160 bombers.
The Soviet Union conducted 715 nuclear tests, second only to the United States. These were primarily at Semipalatinsk Test Site, and Novaya Zemlya, where the most powerful nuclear test ever, the Tsar Bomba at 50 megatons, was conducted in 1961. The Soviet Union, with the US and UK, joined the 1963 Partial Nuclear Test Ban Treaty banning non-underground tests. Its nuclear weapons infrastructure saw many radioactive contamination events; the 1957 Kyshtym disaster remains the worst military accident on the International Nuclear and Radiological Event Scale.
The global Cold War saw many nuclear crises. During the 1962 Cuban Missile Crisis, Soviet nuclear warheads and missiles were briefly stationed in Cuba, often considered the closest call with World War III. Nuclear tensions again crescendoed during the 1969 Sino-Soviet border conflict, as Soviet leadership threatened a massive nuclear attack on China. Soviet nuclear weapons were also stationed in the Warsaw Pact countries of Czechoslovakia, East Germany, Hungary, and Poland, as well as Mongolia and potentially Egypt.
Following the December 1991 dissolution of the Union, tactical warheads stationed across post-Soviet states were withdrawn to Russia by May 1992. Strategic warheads between Belarus, Ukraine, and Kazakhstan were also withdrawn by 1996, under the Lisbon Protocol and Budapest Memorandum.
The Soviet chemical weapons program became the largest in world history. Russia in 1993 declared almost 40,000 tons of chemical weapons. The program produced Novichok, VR, sarin, and soman nerve agents, as well as lewisite, mustard, and phosgene, and others. In 1978, Bulgarian dissident Georgi Markov was killed in London, allegedly with the toxin ricin, by Bulgaria's State Security with the aid of the Soviet KGB.
The Soviet biological weapons program was the world's largest, longest, and most sophisticated biological warfare project. It weaponized and stockpiled the biological agents that cause anthrax, plague, tularemia, smallpox, botulism and others. Genetic engineering improved agent stability and antibiotic resistance. The program employed a peak of 65,000 people and annually produced, for example, 100 tons of smallpox. The Sverdlovsk anthrax leak, which led to at least 68 deaths, began to reveal the extent of the program, continued by defectors including Ken Alibek and Vladimir Pasechnik.
Nuclear weapons
Delivery systems
Strategic
In 1991, the USSR possessed approximately 29,000 nuclear warheads. The Soviet Armed Forces operated a nuclear triad that deployed over 10,000 strategic nuclear weapons: 6,280 warheads assigned to the Strategic Rocket Forces' 1,334 intercontinental ballistic missiles, 3,626 warheads to the Soviet Navy's 914 submarine-launched ballistic missiles, and 974 cruise missiles and bombs to Long Range Aviation's 106 Tu-95MS and Tu-160 bombers. Its most modern strategic missiles were the land-based RT-2PM Topol, RT-23 Molodets, and UR-100N, and submarine-based R-29RM, R-39, and R-29.An estimated 3,000 nuclear weapons tipped surface-to-air missiles, and 100 tipped the ABM-1 and ABM-3 anti-ballistic missile systems around the capital city Moscow.
Tactical
Another 11,000 tactical nuclear weapons were assigned to land and naval tactical aircraft, missiles, nuclear artillery, and anti-submarine weapons including torpedoes and depth charges.Tactical nuclear missiles included the R-17 Elbrus, 9K52 Luna-M, and OTR-21 Tochka. The largest nuclear artillery, 240 mm diameter, were delivered by the M240 towed mortar and 2S4 Tyulpan self-propelled mortar.
Tactical nuclear aircraft included the Mikoyan MiG-27, Sukhoi Su-24 and Su-17 fighters, maritime patrol Beriev Be-12, Ilyushin Il-38, and Tu-142, carrier-based Kamov Ka-27 and Ka-25 helicopters, and Kiev-class carrier-based Yakovlev Yak-38 vertical take-off and landing fighter. The think tank SIPRI considered the long-range bombers the Tu-22M, Tu-95K22, Tu-22 and Tu-16 to be assigned only "non-strategic" warheads, although these aircraft are sometimes considered strategic.
Early development
Production sites
Three sites in the Russian SFSR produced 125.2 tons of weapons-grade plutonium from 1948 to 1991, with a consistent production peak between 1967 and 1989. Following the Moscow test reactor F-1 in 1946, the Mayak site in Chelyabinsk-40 began construction. The first plutonium production reactor A-1 began operation in 1948, fuelling the RDS-1 test. The Mayak site received nine further reactors were constructed. Of these, four were used for plutonium production, the other six reactors primarily produced tritium for thermonuclear weapons. Plutonium was also produced by five reactors at the Siberian Chemical Combine in Tomsk-7, and three reactors at the Mining and Chemical Combine in Krasnoyarsk-26. In this period, Mayak produced 30.9 tons, the Siberian Chemical Combine produced 54.9 tons, and the Mining and Chemical Combine produced 39.4 tons.Russian sites ultimately produced 1,250 tons of highly enriched uranium from 1949 to 2010, excluding HEU produced for naval nuclear reactors. Of this, 500 tons was downblended by the Megatons to Megawatts Program, and a further hundred tons were used in production research reactors, nuclear tests, and other downblending programs. Russia is now believed to possess 656 tons between HEU stockpiles and HEU inside weapons themselves. This began with the SU-20 electromagnetic separation plant, but the Soviet project quickly followed the Manhattan Project's gaseous diffusion scheme, constructing the D-1 plant in Sverdlovsk-44, eventually becoming the Ural Electrochemical Combine. The D-1 plant could produce 0.01 million SWU/year. The development of the gas centrifuge and waves of modernizations brought the Ural Electrochemical Combine to 11.9 million SWU/year by 1993. Further enrichment plants were built at the Siberian Chemical Combine, the Zelenogorsk Electrochemical Plant and the Angarsk Electrochemical Combine.File:Satellite image map of Mayak.jpg|thumb|Satellite imagery of Mayak, a major production site of plutonium and tritium for nuclear weapons during the Soviet era.
Nuclear testing
The Soviet Union used three major test sites: Semipalatinsk in Kazakhstan, Novaya Zemlya in the extreme north, and Kapustin Yar.Notable tests at Semipalatinsk following RDS-1 include RDS-4, the first Soviet tactical nuclear weapon, RDS-6s, the first Soviet weapon to use thermonuclear reactions in a layer cake design, sometimes called a boosted fission weapon, and RDS-37, the first Soviet true two-stage thermonuclear weapon.
Novaya Zemlya was the site of further megaton-range explosions, including the Tsar Bomba, the largest weapon ever detonated, and the Raduga live test of an R-13 submarine-launched ballistic missile. Kapustin Yar was used for high-altitude nuclear tests launched by missiles, including the 1961 tests and Project K tests.
The Soviet Army also conducted the Totskoye nuclear exercise in Orenburg Oblast, 1954, in which 45,000 soldiers and hundreds of tanks, self-propelled guns, and armored personnel carriers were maneuvered through the blast zone of an RDS-4 nuclear bomb. After the 1963 Partial Nuclear Test Ban Treaty, underground testing continued at Semipalatinsk and Novaya Zemlya until 1990. The Soviet Union also developed "clean" thermonuclear weapons, including weapons with only deuterium as thermonuclear fuel, used in a brief program of peaceful nuclear explosions.
Espionage and intelligence gathering
During the Eisenhower administration, the US believed that successful aerial reconnaissance of the Soviet Union's nuclear facilities would be more likely than successful human intelligence. Thus it deployed a range of aircraft on overflights, including the Boeing RB-47 Stratojet and later the Lockheed U-2. A U-2 was famously shot down in 1960, causing international embarrassment to the US, after which it began transitioning to reconnaissance satellites. Under Project Genetrix in 1956, the US also launched high-altitude balloons for reconnaissance, which US Secretary of State John Foster Dulles justified saying "international law is obscure on the question of who owns the upper air".The US also attempted a range of methods for a nuclear detonation detection system, including Project Grab Bag's air sampling balloons, and Project Mogul's infrasound monitoring balloons.
On 8 August 1974, the Central Intelligence Agency's Project Azorian obtained Soviet nuclear weapons in the form of nuclear torpedoes, from the sunken wreck of the Soviet submarine K-129. However, the raising ship Glomar Explorer lost the submarine's section containing the R-13 ballistic missiles and nuclear warheads, and codebooks and decoding machines.
In the late Cold War, the US developed a decapitation strike plan codenamed Canopy Wing, which would infiltrate and interfere with Soviet nuclear command and control in the event of conflict, including potentially supplying false commands to Soviet pilots via computer-generated voices.