A Need for New Warheads?

The U.S. government's proposal to build the first new nuclear warhead in two decades raises a host of questions

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


At this very moment, hundreds of U.S. nuclear warheads and bombs are poised to strike targets in Russia and elsewhere. Despite the demise of the Soviet Union in 1991—and thus the end of the cold war policy of mutually assured destruction—the U.S. maintains a stockpile of roughly 10,000 nuclear weapons. Russia, China, France, India, Israel, Pakistan and the U.K. are now all U.S. allies or, at worst, nonbelligerent competitors. All but Russia possess only limited nuclear arsenals. North Korea and Iran, whose relations with the U.S. are more strained, do not yet have the capability to inflict massive nuclear harm on this nation. Indeed, the most pressing nuclear hazard appears to be a “dirty bomb”—a conventional bomb packed with radioactive material—or a small nuclear explosive. A massive nuclear arsenal may provide little deterrent against the use of such weapons by terrorists or nonstate entities.

As part of its obligations under the Moscow Treaty on Strategic Offensive Reductions, the U.S. plans to reduce its total number of active nuclear weapons to between 1,700 and 2,200 warheads and bombs. At the same time, the U.S. Department of Energy and the Department of Defense, worried that aging warheads may not operate optimally after years of storage, want to replace some of them. First on the list is the W76, which makes up a third of the available warheads; the oldest W76s will reach the end of their 30-year life span in 2008. An individual W76 nuclear explosive generates 100 kilotons of force when detonated, equal to 100,000 tons of TNT; it is designed to obliterate “soft targets,” such as ports, garrisons and factories.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe