‘Countdown’ takes stock of the U.S. nuclear weapons stockpile
Physicists at nuclear weapons labs reveal their motivations in the book
![a nuclear intercontinental ballistic missile in a silo](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2024/03/030924_reviews_feat.jpg?fit=1030%2C580&ssl=1)
The United States is working to modernize its aging nuclear weapons, such as the nuclear intercontinental ballistic missile (shown).
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