How the US and South Korea Predict a North Korean Weapons Test

A missile’s disconnected fuel hose. The frequency of military communication. Even the number of people playing volleyball near a nuclear test site.

The U.S. and South Korea rely on all kinds of clues to guess at what’s going on in North Korea, one of the world’s most secretive countries. Now they are being more open about that intelligence, providing a clearer view of when Pyongyang is preparing a major weapons test.