At the beginning of the nuclear age, the United States initially aimed to maintain a monopoly on atomic weapons. However, the knowledge and technology required to develop nuclear bombs soon proliferated. The United States first tested a nuclear explosive in July 1945 and infamously deployed atomic bombs on Hiroshima and Nagasaki, Japan, in August 1945. Just four years later, the Soviet Union detonated its first nuclear device. The United Kingdom (1952), France (1960), and China (1964) subsequently joined the ranks of nuclear-weapon states. In an effort to limit the expansion of nuclear arsenals, the United States and other nations pursued the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 1968 and the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1996.
Despite these efforts, India, Israel, and Pakistan never signed the NPT and have developed their own nuclear weapon stockpiles. Iraq, under Saddam Hussein, initiated a clandestine nuclear program prior to the 1991 Persian Gulf War. North Korea withdrew from the NPT in January 2003 and has since conducted several nuclear tests, demonstrating advancements in its nuclear capabilities. Iran and Libya have also engaged in covert nuclear activities that violated the NPT, and Syria is suspected of similar actions. Nevertheless, nonproliferation efforts have largely been successful, preventing the widespread nuclear proliferation that was once feared.
During the Cold War, both the United States and the Soviet Union/Russia amassed tens of thousands of nuclear warheads. Starting in the 1970s, a series of bilateral arms control agreements and initiatives between the U.S. and the Soviet Union/Russia aimed to limit and reduce the size of their massive nuclear arsenals.
Currently, the United States has 1,419 and Russia has 1,549 strategic warheads deployed on various bombers and missiles. Both nations are actively modernizing their nuclear delivery systems. These warhead numbers are counted according to the New START agreement, which was extended in January 2021 for five years. While Russia suspended its participation in New START in February 2023, leading to countermeasures from the United States, both countries remain committed to the treaty’s central limits on strategic force deployments until 2026.
The New START treaty sets a limit of 1,550 deployed strategic warheads for each country. It counts warheads on deployed heavy bombers as one per bomber, regardless of the actual number carried. For Intercontinental Ballistic Missiles (ICBMs) and Submarine-Launched Ballistic Missiles (SLBMs), warheads are counted by the number of re-entry vehicles, each capable of carrying a single warhead.
The United States, Russia, and China also possess non-strategic or tactical nuclear warheads, which are shorter-range, lower-yield weapons not subject to treaty limitations.
China, India, and Pakistan are actively developing new ballistic missiles, cruise missiles, and sea-based nuclear delivery systems, further complicating the global nuclear landscape. North Korea continues its nuclear weapons development, despite previous denuclearization pledges.
As of March 2024, the world’s nuclear-armed states collectively possess approximately 12,100 nuclear warheads.
Global map showing estimated nuclear warhead inventories by country in 2025, highlighting disparities in nuclear weapons distribution worldwide.
Comparing Nuclear-Weapon States: The NPT Recognized Powers
The five nuclear-weapon states (NWS) recognized by the NPT are China, France, Russia, the United Kingdom, and the United States. While the NPT acknowledges their existing nuclear arsenals, Article VI of the treaty commits them to eventual nuclear disarmament. In 2000, these NWS made an “unequivocal undertaking” towards the total elimination of their nuclear arsenals. Due to government secrecy, the figures for nuclear arsenals are estimates, encompassing both strategic and tactical nuclear weapons.
Russia: A Nuclear Superpower Compared
Russia possesses a vast nuclear arsenal, a legacy of the Soviet Union. It maintains a triad of land-based missiles, submarine-launched ballistic missiles, and strategic bombers. Russia’s nuclear doctrine has been a subject of international scrutiny, particularly its stance on the potential use of tactical nuclear weapons in regional conflicts. Compared to other NWS, Russia’s arsenal is the largest in terms of warheads, although it is currently capped by the New START treaty in terms of deployed strategic warheads with the United States.
United States: Nuclear Arsenal in Comparison
The United States, like Russia, operates a nuclear triad. The U.S. has been modernizing its nuclear forces, focusing on maintaining a credible deterrent. Historically, the U.S. and Russia have been in a nuclear arms race, but in recent decades, arms control agreements have aimed to manage and reduce their arsenals. When comparing the US and Russia, while both have similar strategic capabilities, their doctrines and modernization priorities differ.
China: A Growing Nuclear Arsenal Compared to Others
Independent research suggests China possesses approximately 440 nuclear warheads, deliverable by land, sea, and air. Around 310 warheads are assigned to strategic launchers. The U.S. Department of Defense estimates China’s total nuclear weapons at 600 as of December 2024, projecting a potential increase to 1000 deliverable warheads by 2030 if current trends continue. China’s nuclear arsenal is smaller compared to the US and Russia, but it is rapidly expanding and modernizing, raising concerns about regional and global nuclear balance. Unlike the US and Russia, China has historically maintained a policy of “no first use” of nuclear weapons.
France: A Smaller but Modern Nuclear Force Compared
France maintains a military stockpile of 290 operational warheads as of January 2022, deployed on 98 strategic delivery systems, including submarine-launched ballistic missiles and air-launched cruise missiles. France is committed to modernizing its nuclear forces but has stated it does not intend to increase its stockpile size. Compared to the larger arsenals of the US, Russia, and China, France’s nuclear force is considerably smaller, focused on deterrence and European security.
United Kingdom: Sea-Based Deterrent Compared
As of January 2022, the United Kingdom possesses a military stockpile of 225 warheads, with approximately 120 operationally available on submarine-launched ballistic missiles. The UK relies exclusively on a sea-based nuclear deterrent, consisting of four Vanguard-class Trident nuclear-powered ballistic missile submarines. The UK’s arsenal is the smallest among the NWS, prioritizing a continuous at-sea deterrent capability.
Non-NPT Nuclear Weapons Possessors: Comparing India, Pakistan, and Israel
India, Pakistan, and Israel, which never joined the NPT, are known to possess nuclear weapons. India conducted its first nuclear test in 1974, prompting Pakistan to accelerate its nuclear weapons program. Both India and Pakistan publicly demonstrated their nuclear capabilities with tests in 1998. Israel is widely believed to possess nuclear weapons but maintains a policy of ambiguity.
India: Regional Nuclear Power Compared to Pakistan
India is estimated to have a growing nuclear arsenal. Its nuclear doctrine is centered around “credible minimum deterrence” and “no first use” against non-nuclear weapon states. India’s nuclear program is largely seen as a response to China, but it is also in a regional nuclear arms race with Pakistan.
Pakistan: Nuclear Arsenal Compared to India
Pakistan developed nuclear weapons primarily in response to India. It is believed to rely on highly enriched uranium for its weapons. Pakistan’s nuclear doctrine is focused on deterrence against India, and it has expressed concerns about India’s “no first use” policy, maintaining a posture of “first use” in certain scenarios.
Israel: Ambiguous Nuclear Status Compared
Israel is estimated to have 90 nuclear warheads, with fissile material for approximately 200. Israel neither confirms nor denies possessing nuclear weapons, stating it will not be the first to introduce nuclear weapons in the Middle East. Israel’s nuclear ambiguity is seen as a deterrent in a volatile region.
Bar chart comparing estimated nuclear warhead inventories of different countries in 2025, visually representing the scale of nuclear arsenals.
States That Declared NPT Withdrawal: North Korea Compared
North Korea joined the NPT but announced its withdrawal in 2003, a move not legally recognized by other NPT members. North Korea has conducted nuclear tests and developed nuclear-capable ballistic missiles.
North Korea: A Developing Nuclear Threat Compared
North Korea is estimated to have around 30 nuclear warheads, with potential for more. There is significant uncertainty surrounding these estimates. North Korea continues to develop its nuclear and missile programs, posing a unique proliferation challenge. Its pursuit of tactical nuclear weapons and ICBMs raises regional and international security concerns.
States of Immediate Proliferation Concern: Iran Compared
Iran is considered a threshold state, having developed the capacity to build nuclear weapons. Iran has threatened to withdraw from the NPT and pursue nuclear weapons if its security situation changes.
Iran: Nuclear Ambitions Compared to Past Programs
Iran ratified the NPT in 1970 but pursued illicit nuclear activities until 2003. In 2015, Iran agreed to the JCPOA to limit its nuclear program in exchange for sanctions relief. However, the U.S. withdrew from the JCPOA in 2018, and Iran has since breached some of its restrictions. While Iran denies seeking nuclear weapons, it has accumulated enough enriched uranium to potentially build them. Iran’s nuclear program remains a major international concern, particularly when compared to states that have abandoned or dismantled their nuclear weapons efforts.
States With Former Nuclear Programs: A Comparison of Disarmament
Several states, including Belarus, Kazakhstan, Ukraine, South Africa, Iraq, Libya, Argentina, Brazil, South Korea, Sweden, Australia, and Taiwan, have had nuclear weapons or programs in the past. Belarus, Kazakhstan, and Ukraine inherited nuclear weapons after the Soviet collapse but returned them to Russia. South Africa dismantled its nuclear weapons program before transitioning to democracy. Iraq and Libya were forced to abandon or voluntarily renounced their nuclear ambitions. These cases demonstrate successful instances of nuclear disarmament and nonproliferation, contrasting with ongoing proliferation challenges.
Conclusion: The Complex Landscape of Nuclear Bombs Compared
Comparing nuclear arsenals globally reveals a complex and dynamic landscape. While the total number of nuclear weapons has decreased from Cold War peaks, thousands remain, primarily in the hands of the US and Russia. The rise of new nuclear powers, modernization efforts, and regional tensions continue to pose significant challenges to nuclear nonproliferation and disarmament. Understanding the nuances of each nation’s nuclear capabilities and doctrines is crucial for navigating this complex global security issue.
Sources: Arms Control Association, Federation of American Scientists, International Panel on Fissile Materials, U.S. Department of Defense, U.S. Department of State, and Stockholm International Peace Research Institute.
