The alert appeared on cellphones warning people to “seek immediate shelter,” and said, “This is not a drill.” The authorities said it was a false alarm.
Buried in an emergency funding request to Congress lie hints of new ways to confront Pyongyang, like cyberweapons and armed drones.
North Korea’s nuclear detonation over the weekend spurred the deployment of the rest of the Terminal High Altitude Area Defense, which is designed to stop missiles from the North.
Days after another missile launch from North Korea, the United States tested its intercept capabilities off the coast of Hawaii.
In the face of stiff opposition, Dr. Keyworth was a strong advocate of the antimissile plan known as Star Wars.
The United States uses two different categories of missile defense to counter North Korea. Here’s how they work and — sometimes — how they don’t.