A key feature of the Cold War was the stockpiling of large numbers of nuclear weapons by both sides. This reached a peak in 1986, at which time the United States possessed approximately 23,000 warheads while the Soviet Union had over 40,000. The figures dropped as weapons were withdrawn from service, but when the Soviet Union was dissolved in 1991 it still possessed some 28,000 operational warheads. The majority of these have since been destroyed, although some remain in service to this day.
The Soviet Nuclear Arsenal
The most potent weapon of the Cold War was the intercontinental ballistic missile, a surface-to-surface weapon capable of delivering a number of separate warheads over a distance of thousands of miles. In addition to ICBMs, the Soviet Union possessed shorter range surface-launched missiles as well as air-launched missiles and bombs. These weapons were stationed in four of the former Soviet republics that became independent states at the end of 1991: Russia, Belarus, Ukraine and Kazakhstan.
Ukraine, Kazakhstan and Belarus
After the collapse of the Soviet Union, the newly independent country of Ukraine inherited approximately 5,000 nuclear warheads. More than 1,200 of these were deployed on long-range ICBMs. Kazakhstan had a similar number of ICBM warheads, while Belarus was the smallest of the post-Soviet nuclear states, with about 80 warheads. All three countries chose voluntarily to divest themselves of their nuclear arsenals -- the first countries in the world to do so. Some of the weapons were destroyed while others were transferred to Russia. The denuclearization of Ukraine, Kazakhstan and Belarus was completed by 1996.
Russia's Nuclear Weapons
Since the end of the Cold War, Russia and the United States have engaged in a series of bilateral talks aimed at reducing the number of nuclear weapons possessed by both countries. As a result, the Russian stockpile has steadily diminished, in step with a similar reduction in U.S. weapon numbers. This is not a move toward total disarmament, however. As the surviving weapons from the Cold War era become obsolete, they are being refurbished or replaced by more modern designs. Russia, like America, still has a potent nuclear weapons capability.
The Current Situation
In January 2013, Russia was estimated to possess approximately 8,500 nuclear warheads, of which 1,800 were actively deployed. These figures are destined to be reduced under the terms of the New Strategic Arms Reduction Treaty, or New START, which was signed by Russian President Dmitry Medvedev and U.S. President Barack Obama on April 8, 2010. This treaty limits the number of operational nuclear warheads on both sides to no more than 1,550, to be achieved no later than February 2018.