Preventing the spread of nuclear weapons presents an enormous challenge.
What Is Nuclear Proliferation?
Why do countries develop nuclear weapons—and what is being done to stop the spread of these weapons?
How Do Countries Create Nuclear Weapons?
The same process used to generate nuclear power can be used to create the most destructive force we know.
(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
The Nuclear Nonproliferation Treaty
How effective is the world’s biggest effort to prevent nuclear proliferation?
The History of Nuclear Proliferation
What are the most significant attempts to stop the spread of nuclear weapons, and have they succeeded?
Tools of Nonproliferation
From diplomacy to military force, world leaders try to prevent the spread of nuclear weapons in many ways. But how effective are they?
The Nuclear World
Where are the world’s nuclear weapons and who do they protect?
31 countries and areas operate a total of 449 nuclear reactors for generating power. Top countries:
United States: 99
South Africa: Why Countries Acquire and Abandon Nuclear Bombs
What one country’s evolution on nuclear weapons illustrates about disarmament.
Nuclear Proliferation Module Assessment
Questions to check your understanding
Nuclear Proliferation Reading List
Supplemental readings and other resources.
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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A Sharper Choice on North Korea: Engaging China for a Stable Northeast Asia
Photo: Korean Central News Agency via Reuters
On the Iran Nuclear Agreement and its Consequences
Photo: Leonhard Foeger/Reuters
The Unsung Success of Nuclear Nonproliferation
Photo: Kevin Lamarque/Reuters