After the Korean War, the Soviet Union transferred nuclear technology and weapons to the People's Republic of China as an adversary of the United States and NATO. According to Ion Mihai Pacepa, "Khrushchev’s nuclear-proliferation process started with Communist China in April 1955, when the new ruler in the Kremlin consented to supply Beijing a sample atomic bomb and to help with its mass production. Subsequently, the Soviet Union built all the essentials of China’s new military nuclear industry."[16]

Russia is one of the five "Nuclear Weapons States" (NWS) under the Nuclear Non-Proliferation Treaty (NPT), which Russia ratified (as the Soviet Union) in 1968.

Following the dissolution of the Soviet Union in 1991, a number of Soviet-era nuclear warheads remained on the territories of Belarus, Ukraine, and Kazakhstan. Under the terms of the Lisbon Protocol to the NPT, and following the 1995 Trilateral Agreement between Russia, Belarus, and the USA, these were transferred to Russia, leaving Russia as the sole inheritor of the Soviet nuclear arsenal. It is estimated that the Soviet Union had approximately 45,000 nuclear weapons stockpiled at the time of its collapse.

The collapse of the Soviet Union allowed for a warming of relations with NATO. Fears of a nuclear holocaust lessened. In September 1997, the former secretary of the Russian Security Council Alexander Lebed claimed 100 "suitcase sized" nuclear weapons were unaccounted for. He said he was attempting to inventory the weapons when he was fired by President Boris Yeltsin in October 1996.[17] In 2005, Sergey Sinchenko, a legislator from the Yulia Tymoshenko Bloc, said 250 nuclear weapons were unaccounted for. When comparing documents of nuclear weapons transferred from Ukraine to weapons received by Russia, there was a 250-weapon discrepancy.[18] Indeed, several US politicians have expressed worries and promised legislation addressing the threat.[19]

In 2002, the United States and Russia agreed to reduce their stockpiles to not more than 2,200 warheads each in the SORT treaty. In 2003, the US rejected Russian proposals to further reduce each nation's nuclear stockpiles to 1,500. Russia, in turn, refused to discuss reduction of tactical nuclear weapons.[20]

Russia is actively producing and developing new nuclear weapons. Since 1997 it manufactures Topol-M (SS-27) ICBMs.

There were allegations that Russia contributed to North Korean nuclear program, selling it the equipment for the safe storage and transportation of nuclear materials.[21] Nevertheless, Russia condemned Korean nuclear tests since then.[22]

According to high-ranking Russian SVR defector Sergei Tretyakov, a businessman told him that he keeps his own nuclear bomb at his dacha outside Moscow