The RDS-1 (Russian: РДС-1), also known as Izdeliye 501 (Device 501) and First Lightning (Russian: Пе́рвая мо́лния, romanized: Pyérvaya mólniya, IPA: [ˈpʲervəjə ˈmolnʲɪjə]), was the first test of a Soviet nuclear bomb. It was roughly based on the American design, Fat Man, and the United States assigned it the code-name Joe-1, in reference to Joseph Stalin.
It was detonated on 29 August 1949 at 7:00 a.m. MSK (UTC+03:00), at the Semipalatinsk Test Site in the Kazakh Soviet Socialist Republic.
The Cold War was a period of global geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which began in the aftermath of the Second World War and ended with the dissolution of the Soviet Union in 1991. The term cold war is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, embargoes, and sports diplomacy.
After the end of the Second World War in 1945, during which the US and USSR had been allies, the USSR installed satellite governments in its occupied territories in Eastern Europe and North Korea by 1949, resulting in the political division of Europe (and Germany) by an "Iron Curtain". The USSR tested its first nuclear weapon in 1949, four years after their use by the US on Hiroshima and Nagasaki, and allied with the People's Republic of China, founded in 1949. The US declared the Truman Doctrine of "containment" of communism in 1947, launched the Marshall Plan in 1948 to assist Western Europe's economic recovery, and founded the NATO military alliance in 1949 (matched by the Soviet-led Warsaw Pact in 1955). The Berlin Blockade of 1948 to 1949 was an early confrontation, as was the Korean War of 1950 to 1953, which ended in a stalemate.
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.
Nuclear proliferation is the spread of nuclear weapons to additional countries, particularly those not recognized as nuclear-weapon states by the Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT. Nuclear proliferation occurs through the spread of fissile material, and the technology and capabilities needed to produce it and to design and manufacture nuclear weapons. In a modern context, it also includes the spread of nuclear weapons to non-state actors. Proliferation has been opposed by many nations with and without nuclear weapons, as governments fear that more countries with nuclear weapons will increase the possibility of nuclear warfare (including the so-called countervalue targeting of civilians), de-stabilize international relations, or infringe upon the principle of state sovereignty. Conversely, supporters of deterrence theory argue that controlled proliferation decreases conflict rates via nuclear peace.
Nuclear weapons were initially researched during World War II, jointly by the United States, United Kingdom and Canada, and separately by Germany, Japan, the Soviet Union, and France. The United States was the first and is the only country to have used a nuclear weapon in war, when it used two bombs against Japan in August 1945. After surrendering, Germany and Japan ceased to be involved in any nuclear weapon research. A nuclear arms race followed, with further countries developing and testing nuclear weapons. The US primarily competed with the Soviet Union, which carried out their first test in 1949. Seven other countries developed nuclear weapons during the Cold War. The UK and France, both NATO members, developed fission and fusion weapons throughout the 1950s, and 1960s, respectively. China developed both against the backdrop of the Sino-Soviet split.
The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is an international treaty, the objective of which is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy, and to further the goal of achieving nuclear disarmament and general and complete disarmament. Between 1965 and 1968, the treaty was negotiated by the Eighteen Nation Committee on Disarmament, a United Nations-sponsored organization based in Geneva, Switzerland.
Opened for signature in 1968, the treaty entered into force in 1970. As required by the text, after twenty-five years, NPT parties met in May 1995 and agreed to extend the treaty indefinitely. The treaty defines nuclear-weapon states as those that have built and tested a nuclear explosive device before 1967; these are the United States (1945), Russia (1949), the United Kingdom (1952), France (1960), and China (1964).
There are currently nine sovereign states that are generally understood to possess nuclear weapons, though only eight formally acknowledge possessing them. In order of first successful nuclear test, the world's nine nuclear-armed states are the United States (1945), Russia (1949), the United Kingdom (1952), France (1960), China (1964), India (1974), Pakistan (1998), and North Korea (2006); Israel is believed to have acquired nuclear weapons around 1967, but has never openly tested or formally acknowledged having them. Under the Non-Proliferation Treaty (NPT), the United States, Russia, the United Kingdom, France, and China are recognized "nuclear-weapons states" (NWS). They are also the five permanent members of the United Nations Security Council. Israel, India, and Pakistan never signed the NPT, while North Korea acceded to it in 1985 before announcing withdrawal in 2003.
South Africa developed nuclear weapons by 1982 but dismantled them around 1989 and joined the NPT in 1991. Following the dissolution of the Soviet Union in 1991, the former Soviet republics of Ukraine, Kazakhstan, and Belarus had nuclear weapons deployed on their territories, but agreed to transfer them to Russia (which inherited the Soviet Union's international rights and obligations) and join the NPT as non-nuclear-weapon states.