Nuclear weapons haven’t been tested in the United States since 1992. Find out why, and what could happen if the hiatus ends.

A subsurface atomic test near Yucca Flats, Nev., in March 1955. (U.S. Atomic Energy Commission via AP) In what would be a major shift in a decades-old American policy against global nuclear ...

Alex Partezana was a 22-year-old Marine in April 1953 when he received an unusual order: to observe nuclear weapons testing in the desert outside Las Vegas, Nevada. He still remembers the first blast ...

VIENNA (AP) — The United States and Russia have both recently threatened to resume nuclear testing, alarming the international community and jeopardizing a global norm against such tests. Experts say ...