The Doomsday Clock was created in a publication called the Bulletin of the Atomic Scientists in 1947 and was intended as a stark graphical representation of how close the planet Earth is to nuclear annihilation. The minute hand shows the relative time remaining for life on Earth. This is measured in “minutes to midnight.” The minute hand is moved once per year.
At the start of the Cold War (1947), the clock was set at seven minutes to midnight. In 1991, just after the end of the Cold War, the clock showed 17 minutes to midnight.
This year the Bulletin of the Atomic Scientists issued a shocking announcement that The Doomsday Clock was moved forward to 2½ minutes to midnight, the closest to disaster the clock has been since 1953. (At that time, it was set at two minutes to midnight due to a U.S. decision to pursue the hydrogen bomb.)
[As part of the reason] for moving the Doomsday Clock forward to “two and a half minutes to midnight,” The Bulletin cited the North Korean situation.
North Korea has made great strides in short-range and intermediate-range missiles, and is working toward an intercontinental ballistic missile (ICBM), that could reach Los Angeles and much of the rest of the United States from their territory. North Korea also has a store of plutonium and highly-enriched uranium (HEU) that can be converted into nuclear weapons. It has made progress in the miniaturization and ruggedization of those weapons so they can be converted to warheads and placed on the missiles. The only remaining element of the nightmare scenario is intent.