From a high of 65,000 active weapons in 1985, there are now nearly 8,000 active nuclear warheads and about 23,300 total nuclear warheads in the world in 2009. Many of the "decommissioned" weapons were simply stored or partially dismantled, not destroyed. As of 2009, the total number was expected to continue to decline by 30%–50% over the next decade.

Throughout the Cold War it continued to modernize and enlarge its nuclear arsenal, but from 1992 on has been involved primarily in a program of Stockpile stewardship.

       The United Kingdom tested its first nuclear weapon ("Hurricane") in 1952, drawing largely on data gained while collaborating with the United States during the Manhattan Project. The United Kingdom was the third country in the world after the USA and USSR to develop and test a nuclear weapon. Its programme was motivated to have an independent deterrent against the USSR, while also maintaining its status as a great power. It tested its first hydrogen bomb in 1957, making it the third country to do so after the USA and USSR. The UK maintained a fleet of V-bomber strategic bombers and ballistic missile submarines equipped with nuclear weapons during the Cold War. It currently maintains a fleet of four 'Vanguard' class ballistic missile submarines equipped with Trident IISLBMs. The British government announced a replacement to the current system to take place between 2007-2024. 

        France tested its first nuclear weapon in 1960 ("Gerboise Bleue"), based mostly on its own research. It was motivated by the Suez Crisis diplomatic tension vis-à-vis both the USSR and the Free World allies United States and United Kingdom. It was also relevant to retain great power status, alongside the United Kingdom, during the post-colonial Cold War. France tested its first hydrogen bomb in 1968 ("Opération Canopus"). After the Cold War, France has disarmed 175 warheads with the reduction and modernization of its arsenal that has now evolved to a dual system based on submarine-launched ballistic missiles (SSBN) and medium-range air-to-surface missiles (Rafale fighter-bombers). However new nuclear weapons are in development and reformed nuclear squadrons were trained during Enduring Freedom operation in Afghanistan. In January 2006, President Jacques Chirac stated a terrorist act or the use of weapons of mass destruction against France would result in a nuclear counterattack.

  Under NATO nuclear weapons  sharing, the United States has provided nuclear weapons for Belgium, Germany, Italy, the Netherlands, and Turkey to deploy and store. This involves pilots and other staff of the "non-nuclear" NATO states practicing handling and delivering the U.S. nuclear bombs, and adapting non-U.S. warplanes to deliver U.S. nuclear bombs. Until 1984 Canada also received shared nuclear weapons, and until 2001, Greece.

Members of the Non-Aligned Movement have called on all countries to "refrain from nuclear sharing for military purposes under any kind of security arrangements.” The Institute of Strategic Studies Islamabad (ISSI) has criticized the arrangement for allegedly violating Article I and II of the NPT, arguing that "these Articles do not permit the NWS to delegate the control of their nuclear weapons directly or indirectly to others.” NATO has argued that the weapons' sharing is compliant with the NPT because "the U.S. nuclear weapons based in Europe are in the sole possession and under constant and complete custody and control of the United States."

Nuclear weapons have been present in many nations, often as staging grounds under control of other powers. However, in only a few instances have nations given up nuclear weapons after being in control of them; in most cases this has been because of special political circumstances. The fall of the USSR, for example, left several former Soviet-bloc countries in possession of nuclear weapons.

  South Africa produced six nuclear weapons in the 1980s, but disassembled them in the early 1990s. In 1979, there was a putative detection of a clandestine nuclear test in the Indian Ocean, and it has long been speculated that it was possibly a test by South Africa, perhaps in collaboration with Israel, though this has never been confirmed. South Africa signed the Nuclear Non-Proliferation Treaty in 1991.

Former Soviet countries

 Belarus had 81 single warhead missiles stationed on its territory after the Soviet Union collapsed in 1991. They were all transferred to Russia by 1996. Belarus has signed the Nuclear Non-Proliferation Treaty.

 Kazakhstan inherited 1,400 nuclear weapons from the Soviet Union, and transferred them all to Russia by 1995. Kazakhstan has signed the Nuclear Non-Proliferation Treaty.

 Ukraine has signed the Nuclear Non-Proliferation Treaty. Ukraine inherited about 5,000 nuclear weapons when it became independent from the USSR in 1991, making its nuclear arsenal the third-largest in the world. By 1996, Ukraine had voluntarily disposed of all nuclear weapons within its territory, transferring them to Russia.

Former NATO nuclear weapons sharing countries

 Canada Under NATO nuclear weapons sharing, Canada hosted nuclear weapons until 1984.

 Greece Under NATO nuclear weapons sharing, Greece hosted nuclear weapons until 2001.