Nuclear warfare in the context of "Aftermath of World War II"

The Cuban Missile Crisis, also known as the October Crisis (Spanish: Crisis de Octubre) in Cuba, or the Caribbean Crisis (Russian: Карибский кризис, romanized: Karibskiy krizis), was a 13-day confrontation between the governments of the United States and the Soviet Union, when American deployments of nuclear missiles in the United Kingdom, Italy and Turkey were matched by Soviet deployments of nuclear missiles in Cuba. The crisis lasted from 16 to 28 October 1962. The confrontation is widely considered the closest the Cold War came to escalating into full-scale nuclear war.

From 1959, the US government based Thor nuclear missiles in England, known as Project Emily. In 1961, the US put Jupiter nuclear missiles in Italy and Turkey. All were within range of Moscow. The US had trained a paramilitary force of Cuban expatriates, which the CIA led in an attempt to invade Cuba and overthrow its government. Starting in November of that year, the US government engaged in a violent campaign of terrorism and sabotage in Cuba, referred to as the Cuban Project, which continued throughout the first half of the 1960s. The Soviet administration was concerned about a Cuban drift towards China, with which the Soviets had an increasingly fractious relationship. In response to these factors the Soviet and Cuban governments agreed, at a meeting between leaders Nikita Khrushchev and Fidel Castro in July 1962, to place nuclear missiles on Cuba to deter a future US invasion. Construction of launch facilities started shortly thereafter.

Contemporary history, in English-language historiography, is a subset of modern history that describes the historical period from about 1945 to the present. In the social sciences, contemporary history is also continuous with, and related to, the rise of postmodernity.

Contemporary history is politically dominated by the Cold War (1947–1991) between the Western Bloc, led by the United States, and the Eastern Bloc, led by the Soviet Union. The confrontation spurred fears of a nuclear war. An all-out "hot" war was avoided, but both sides intervened in the internal politics of smaller nations in their bid for global influence and via proxy wars. The Cold War ultimately ended with the Revolutions of 1989 and the dissolution of the Soviet Union in 1991. The latter stages and aftermath of the Cold War enabled the democratization of much of Europe, Africa, and Latin America. Decolonization was another important trend in Southeast Asia, the Middle East, and Africa as new states gained independence from European colonial empires during the period from 1945–1975. The Middle East also saw a conflict involving the new state of Israel, the rise of petroleum politics, the continuing prominence but later decline of Arab nationalism, and the growth of Islamism. The first supranational organizations of government, such as the United Nations and European Union, emerged during the period after 1945.

The Sino-Soviet split was the gradual worsening of relations between China and the Union of Soviet Socialist Republics (USSR) during the Cold War. This was primarily caused by divergences that arose from their different interpretations and practical applications of Marxism–Leninism, as influenced by their respective geopolitics during the Cold War of 1947–1991. In the late 1950s and early 1960s, Sino-Soviet debates about the interpretation of orthodox Marxism became specific disputes about the Soviet Union's policies of national de-Stalinization and international peaceful coexistence with the Western Bloc, which Chinese leader Mao Zedong decried as revisionism. Against that ideological background, China took a belligerent stance towards the Western world, and publicly rejected the Soviet Union's policy of peaceful coexistence between the Western Bloc and Eastern Bloc. In addition, Beijing resented the Soviet Union's growing ties with India due to factors such as the Sino-Indian border dispute, while Moscow feared that Mao was unconcerned about the drastic consequences of nuclear warfare.

In 1956, Soviet leader Nikita Khrushchev denounced Joseph Stalin and Stalinism in the speech "On the Cult of Personality and Its Consequences" and began the de-Stalinization of the USSR. Mao and the Chinese leadership were appalled as the PRC and the USSR progressively diverged in their interpretations and applications of Leninist theory. By 1961, their intractable ideological differences provoked the PRC's formal denunciation of Soviet communism as the work of "revisionist traitors" in the USSR. The PRC also declared the Soviet Union social imperialist. For Eastern Bloc countries, the Sino-Soviet split was a question of who would lead the revolution for world communism, and to whom (China or the USSR) the vanguard parties of the world would turn for political advice, financial aid, and military assistance. In that vein, both countries competed for the leadership of world communism through the vanguard parties native to the countries in their spheres of influence. The conflict culminated after the Zhenbao Island Incident in 1969, when the Soviet Union reportedly considered the possibility of launching a large-scale nuclear strike against China, and the Chinese leadership, including Mao, was evacuated from Beijing, before both sides eventually returned to diplomatic negotiations.

The nuclear arms race was an arms race competition for supremacy in nuclear warfare between the United States, the Soviet Union, and their respective allies during the Cold War. During this same period, in addition to the American and Soviet nuclear stockpiles, other countries developed nuclear weapons, though no other country engaged in warhead production on nearly the same scale as the two superpowers.

The race began during World War II, dominated by the Western Allies' Manhattan Project and Soviet atomic spies. Following the atomic bombings of Hiroshima and Nagasaki, the Soviet Union accelerated its atomic bomb project, resulting in the RDS-1 test in 1949. Both sides then pursued an all-out effort, realizing deployable thermonuclear weapons by the mid-1950s. The arms race in nuclear testing culminated with the 1961 Tsar Bomba. Atmospheric testing was ended in the 1963 Partial Nuclear Test Ban Treaty. Subsequent work focused on the miniaturization of warheads at LLNL and VNIITF, and the neutron bomb.

On 6 and 9 August 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki, respectively, during World War II. The aerial bombings killed 150,000 to 246,000 people, most of whom were civilians, and remain the only uses of nuclear weapons in an armed conflict. Japan announced its surrender to the Allies on 15 August, six days after the bombing of Nagasaki and the Soviet Union's declaration of war against Japan and invasion of Manchuria. The Japanese government signed an instrument of surrender on 2 September, ending the war.

In the final year of World War II, the Allies prepared for a costly invasion of the Japanese mainland. This undertaking was preceded by a conventional bombing and firebombing campaign that devastated 64 Japanese cities, including an operation on Tokyo. The war in Europe concluded when Germany surrendered on 8 May 1945, and the Allies turned their full attention to the Pacific War. By July 1945, the Allies' Manhattan Project had produced two types of atomic bombs: "Little Boy", an enriched uranium gun-type fission weapon, and "Fat Man", a plutonium implosion-type nuclear weapon. The 509th Composite Group of the U.S. Army Air Forces was trained and equipped with the specialized Silverplate version of the Boeing B-29 Superfortress, and deployed to Tinian in the Mariana Islands. The Allies called for the unconditional surrender of the Imperial Japanese Armed Forces in the Potsdam Declaration on 26 July 1945, the alternative being "prompt and utter destruction". The Japanese government ignored the ultimatum.

Cuba, officially the Republic of Cuba, is an island country in the Caribbean. It comprises 4,195 islands, islets and cays, including the eponymous main island and Isla de la Juventud. Situated at the confluence of the Caribbean Sea, Gulf of Mexico, and Atlantic Ocean, Cuba is located east of the Yucatán Peninsula, south of both Florida (the United States) and the Bahamas, west of Hispaniola (Haiti and the Dominican Republic), and north of Jamaica and the Cayman Islands. Havana is the largest city and capital. Cuba is the third-most populous country in the Caribbean after Haiti and the Dominican Republic, with about 10 million inhabitants. It is the largest country in the Caribbean by area. Culturally, Cuba is considered part of Latin America.

Cuba was inhabited as early as the fourth millennium BC, with the Guanahatabey and Taíno peoples present at the time of Spanish colonization in the 15th century. Cuba remained part of the Spanish Empire until the Spanish–American War of 1898, after which it was occupied by the United States and gained independence in 1902. A 1933 coup toppled the democratically elected government of Carlos Manuel de Céspedes y Quesada and began a long period of military influence, particularly by Fulgencio Batista. In 1940, Cuba implemented a new constitution, but mounting political unrest culminated in the 1952 Cuban coup d'état by Batista. His autocratic government was overthrown in January 1959 by the 26th of July Movement during the Cuban Revolution. That revolution established communist rule under the leadership of Fidel Castro. The country under Castro was a point of contention during the Cold War between the Soviet Union and the United States, and the Cuban Missile Crisis of 1962 is widely considered the closest the Cold War came to escalating into nuclear war.

Nuclear winter is a severe and prolonged global climatic cooling effect that is hypothesized to occur after widespread urban firestorms following a large-scale nuclear war. The hypothesis is based on the fact that such fires can inject soot into the stratosphere, where it can block some direct sunlight from reaching the surface of the Earth. It is speculated that the resulting cooling, typically lasting a decade, would lead to widespread crop failure, a global nuclear famine, and an animal mass extinction event.

Climate researchers study nuclear winter via computer models and scenarios. Results are highly dependent on nuclear yields, weather and how many cities are targeted, their flammable material content, and the firestorms' atmospheric environments, convections, and durations. Firestorm case studies include the World War II bombings of Hiroshima, Tokyo, Hamburg, Dresden, and London, and modern observations from large-area wildfires such as the 2021 British Columbia wildfires.