Nuclear weaponsOverall number of nuclear warheads decreases, but modernization of world nuclear forces continues

The modernization of nuclear forces continues, even as the overall number of nuclear warheads continues to decline. At the start of 2019, nine states—the United States, Russia, the United Kingdom, France, China, India, Pakistan, Israel and the Democratic People’s Republic of Korea (North Korea)—possessed approximately 13,865 nuclear weapons. This marked a decrease from the approximately 14,465 nuclear weapons that SIPRI estimated these states possessed at the beginning of 2018.

SIPRI Governing Board Chair Ambassador Jan Eliasson, former Deputy Secretary-General of the United Nations, says: “A key finding is that despite an overall decrease in the number of nuclear warheads in 2018, all nuclear weapon-possessing states continue to modernize their nuclear arsenals.”

Information gathered in SIPRI Yearbook 2019 shows that of these 13,865 nuclear weapons, 3,750 are deployed with operational forces and nearly 2,000 of these are kept in a state of high operational alert.

SIPRI says that the decrease in the overall number of nuclear weapons in the world is due mainly to Russia and the United States—which together still account for over 90 percent of all nuclear weapons—further reducing their strategic nuclear forces pursuant to the implementation of the 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) while also making unilateral reductions. In 2018, Russia and the USA announced that they had achieved the final New START force reduction limits by the specified deadline.

New START will expire in 2021 unless both parties agree to extend it. There are currently no discussions about extending New START or negotiating a follow-on treaty. “The prospects for a continuing negotiated reduction of Russian and US nuclear forces appears increasingly unlikely given the political and military differences between the two countries,” says Shannon Kile, Director of SIPRI’s Nuclear Disarmament, Arms Control and Non-proliferation Program.

Both Russia and the United States have extensive and expensive programs under way to replace and modernize their nuclear warheads, missile and aircraft delivery systems, and nuclear weapon production facilities. In 2018, the U.S. Department of Defense set out plans to develop new nuclear weapons and modify others to give them expanded military roles and missions.

The nuclear arsenals of the other nuclear-armed states are considerably smaller, but all are either developing or deploying new weapon systems or have announced their intention to do so. China, India and Pakistan are increasing the size of their nuclear arsenals. “India and Pakistan are expanding their military fissile material production capabilities on a scale that may lead to significant increases in the size of their nuclear weapon inventories over the next decade,” says Kile.

North Korea continues to prioritize its military nuclear program as a central element of its national security strategy, although in 2018 it announced a moratorium on the testing of nuclear weapons as well as medium- and long-range ballistic missile delivery systems.

SIPRI notes that the availability of reliable information on the status of the nuclear arsenals and capabilities of the nuclear-armed states varies considerably.

The United States and the United Kingdom have disclosed important information about their stockpile and nuclear capabilities, and France has also declared some information. Russia does not make publicly available a detailed breakdown of its forces counted under New START, even though it shares this information with the United States.

The governments of India and Pakistan make statements about some of their missile tests but provide little information about the status or size of their arsenals. At present, North Korea has acknowledged conducting nuclear weapon and missile tests but provides no information about its nuclear weapon capabilities. Israel has a long-standing policy of not commenting on its nuclear arsenal.