Prohibiting the spread of nuclear weapons presents an enormous challenge.
Explore the past, present, and future threats that nuclear weapons pose.
(about 55 pounds) of highly enriched uranium or 8 kilograms (about 18 pounds) of plutonium is needed to make an elementary nuclear weapon.
Source: Belfer Center and IAEA
Walk through the basics of nuclear reactions.
The Treaty on the Nonproliferation of Nuclear Weapons
Learn about the major diplomatic effort to stop the spread of nuclear weapons.
The History of Nuclear Proliferation
Learn about important moments in the spread of nuclear weapons and world leaders’ attempts to contain them.
Tools of Nonproliferation
Analyze the diplomatic tools world leaders have at their disposal to stem to spread of nuclear weapons.
31 countries and areas operate a total of 449 nuclear reactors for generating power. Top countries:
United States: 99
The Nuclear World
Look at the nuclear status quo to see where nuclear stockpiles exist.
Why States Acquire and Abandon the Bomb
Study the case of South Africa, which provides unique insight into the motivations for countries to both develop and abandon nuclear weapons programs.
How Nuclear Proliferation Affects You
Source: Lee Jae-Won/Reuters
What Would Happen in the Minutes and Hours After North Korea Nuked the United States
A step-by-step account of a hypothetical North Korean nuclear attack—and how the United States and others might respond.
Source: Shannon Stapleton/Reuters
Why America Can’t Spot Dirty Bombs
The U.S. government would struggle to detect a terrorist attack using radiation and to communicate and respond effectively, according to an evaluation by the Department of Homeland Security itself.
Source: Vincent Kessler/Reuters
The World’s First Permanent Nuclear-Waste Repository
Finland is close to finishing construction of a storage site, but the real challenge will be keeping it protected for hundreds of millennia.
Source: Yuri Gripas/Reuters
Top Commander Says Banning Nukes Would Make Wars Worse
The general in charge of U.S. nuclear forces argues that nuclear weapons keep wars—and their death tolls—smaller than they would otherwise be.
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Photo: Korean Central News Agency via Reuters
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Photo: Leonhard Foeger/Reuters
The Unsung Success of Nuclear Nonproliferation
Photo: Kevin Lamarque/Reuters