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Country Spotlight

In July 1945, the United States conducted the first nuclear test, and one month later became the first and only country to use nuclear weapons in war. The U.S. currently maintains one of the world’s largest nuclear arsenals with a triad of delivery systems. Preventing the spread of weapons of mass destruction is traditionally a top priority of U.S. foreign policy.

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Region   North America

3,708 Strategic nuclear warheads (~1,770 warheads deployed and ~1,938 held in reserve)

~1,336 Nuclear warheads awaiting dismantlement

100 Nuclear gravity bombs deployed to five NATO countries as part of extended deterrence policy

$634 billion Estimated cost of nuclear forces in the 2020s


  • Manhattan Project during WWII developed world's first nuclear reactor and nuclear bomb
  • Peak stockpile size of 31,255 nuclear warheads in 1967
  • Conducted 1,054 nuclear tests between 1945-1992, unilateral testing moratorium since 1992

United States Nuclear Overview


  • Maintained biological weapons program from 1943-1973; weaponized anthrax, tularemia, VEE, Botulinum Toxin, and staphylococcal enterotoxin B (SEB)
  • Renounced biological weapons in 1969; destroyed entire BW stockpile by 1973
  • Maintains extensive biodefense laboratory network

United States Biological Overview


  • Deploys 400 LGM-30G Minuteman III nuclear-tipped intercontinental ballistic missiles (ICBM) at bases in Montana, North Dakota, and Wyoming
  • Deploys 280 UGM-133A Trident II D-5 submarine launched ballistic missiles (SLBM) on 14 Ohio-class nuclear-powered ballistic missile submarines (SSBN)
  • Developing missiles formerly banned by Intermediate-Range Nuclear Forces Treaty (INF), from which U.S. withdrew in 2019

United States Missile Overview


  • Manufactured, stockpiled, and used mustard gas and phosgene during WWI
  • Signed the Bilateral Destruction Agreement (BDA) in 1990, halting all production of new U.S. and Soviet chemical weapons
  • Completed the destruction of its chemical weapon stockpiles in July 2023

United States Chemical Overview

Treaties and Regimes Memberships

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The NPT is a treaty aimed at limiting the spread of nuclear weapons through the three pillars of non-proliferation, disarmament, and peaceful use of nuclear energy.

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Biological Weapons Convention (BWC)

The BTWC mandates the elimination of existing biological weapons and prohibits developing, stockpiling, or using biological and toxin weapons.

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Chemical Weapons Convention (CWC)

The Chemical Weapons Convention (CWC) requires countries to destroy all chemical weapons and prohibits developing, stockpiling, or using chemical weapons.

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North Atlantic Treaty Organization (NATO)

NATO was founded in 1949 and has 32 Alliance Members. Its member countries are committed to sharing the risks and responsibilities as well as the benefits of collective security.

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United States

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Education Center

Extensive resources on nuclear policy, biological threats, radiological security, cyber threats and more.

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U.S. Department of State, Fact Sheet: Transparency in the U.S. Nuclear Weapons Stockpile, October 5, 2021, www.state.gov.

Robert S. Norris and Hans M. Kristensen, “United States Nuclear Forces, 2022,” Bulletin of the Atomic Scientists 78, No. 3, www.thebulletin.org.

“Projected Cost of U.S. Nuclear Arsenal Rises | Arms Control Association,” Accessed July 13, 2021, www.armscontrol.org.

Hans M. Kristensen and Robert Norris, “Global Nuclear Weapons Inventories, 1945-2009,” Bulletin of the Atomic Scientists 65, No. 4, 2009, www.thebulletin.org.

Jeanne Guillemin, Biological Weapons: From the Invention of State-sponsored Programs to Contemporary Bioterrorism, (New York: Columbia University Press, 2005).

Jonathon B. Tucker, War of Nerves: Chemical Warfare from World War I to Al-Qaeda (New York: Anchor Books, 2007).

Kingston Reif and Shannon Bugos, “U.S. Tests Second Medium-Range Missile,” Arms Control Today, January/February 2020, www.armscontrol.org.

Hans M. Kristensen, Matt Korda, Eliana Johns, and Mackenzie Knight, “United States nuclear weapons, 2024,” Bulletin of the Atomic Scientists, Vol. 80, No. 3 (2024), pp. 182-208.


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