No abstract

The authors calculate that some 125,000 nuclear warheads have been built since 1945, about 97 percent of them by the United States and the Soviet Union and Russia. The nine nations with nuclear weapons now possess more than 10,000 nuclear warheads in their military stockpiles, the authors estimate, with several thousand additional US and Russian retired warheads in storage, awaiting dismantlement. The nuclear stockpiles of China, as well as Pakistan, India, Israel, and North Korea, are minuscule in comparison with the US and Russian arsenals, but more difficult to estimate. Still, the authors believe that ChinaÕs nuclear weapons stockpile has surpassed Great BritainÕs. Although the total number of nuclear warheads in the world is decreasing because of US and Russian reductions, all the nations with nuclear weapons continue to modernize or upgrade their nuclear arsenals.

Pakistan has a nuclear weapons stockpile of 130-140 warheads and appears to have plans to increase its arsenal further. With several delivery systems in development, four plutonium production reactors, and expansion of uranium enrichment facilities, the country's stockpile will likely increase over the next 10 years, but by how much will depend on many things. Two key factors will be how many nuclear-capable launchers Islamabad plans to deploy, and how much the Indian nuclear arsenal grows. Based on Pakistan's performance over the past 20 years and its current and anticipated weapons deployments, the authors estimate that its stockpile could potentially grow to 220-250 warheads by 2025, making it the world's fifth-largest nuclear weapon state. Pakistan's deployment of short-range, so-called tactical nuclear weapons is causing considerable concern in South Asia and in the US Government about warhead security and lowering of the threshold for nuclear weapons use.

No abstract

As of mid-2014, the authors estimate that there are approximately 16,300 nuclear weapons located at some 98 sites in 14 countries. Roughly 10,000 of these weapons are in military arsenals; the remaining weapons are retired and awaiting dismantlement. Approximately 4,000 are operationally available, and some 1,800 are on high alert and ready for use on short notice. The largest concentrations of nuclear weapons reside in Russia and the United States, which possess 93 percent of the total global inventory. The United States today stores nuclear weapons at 18 sites, including 12 sites in 11 states in the United States and another six sites in five European countries. There is considerable uncertainty about the number of Russian nuclear weapons storage sites, but the authors estimate that Russia today stores nuclear weapons permanently at 40 domestic locations.