Bombers to ICBMs: a Cold War contest measured in megatons
The nuclear arms race was the Cold War competition for nuclear supremacy between the United States, the Soviet Union, and their allies. It began with the Manhattan Project and Soviet espionage, then accelerated after Hiroshima and Nagasaki when Moscow raced for its own bomb.
Four wartime programmes chased the bomb, but only the American-led Manhattan Project, run with Britain's Tube Alloys effort and Canada, built one; Soviet, German and Japanese research stayed far smaller. Spies fed Moscow secrets, and after Hiroshima and Nagasaki the Soviets pushed hard enough to test RDS-1 in 1949. Both powers had usable hydrogen bombs by the mid-1950s, and the testing contest peaked with the Tsar Bomba in 1961 before the 1963 Partial Test Ban Treaty moved explosions underground.
Engineering then turned to smaller, lighter, cleaner warheads and neutron-bomb variants, led by Los Alamos and Livermore in America and VNIIEF and VNIITF in the Soviet Union. Delivery mattered as much as yield. Bombers were the only option at first, but by 1960 both sides fielded land-based and submarine-launched ballistic missiles, completing the so-called triad, alongside tactical systems ranging from nuclear artillery to depth bombs and torpedoes. Weapons were stationed across the Warsaw Pact and in West Germany, Italy, Greece, Turkey, Japan, South Korea, Taiwan and the Philippines.
Seven other states went nuclear during the Cold War: Britain in the 1950s and France in the 1960s, China amid its split with Moscow, and Israel, India, Pakistan and South Africa with at least fission devices. None came close to superpower output. Nuclear threats hung over Korea, two Taiwan Strait crises, Berlin in 1961 and above all Cuba.
Détente brought the Non-Proliferation and Anti-Ballistic Missile treaties, but the early 1980s reheated things with new European missiles and the space-based Strategic Defense Initiative. Gorbachev's Soviet Union signed the INF Treaty and START I before its 1991 collapse ended the race. Later deals included START II in 1993, the test-ban treaty of 1996 and New START in 2010, yet INF lapsed in 2019 and New START in 2023, Russia touts six new super weapons, and Washington and Beijing now compete over hypersonic arms.
Source: Nuclear arms race
