Nuclear security

Rocket Men: The team building North Korea's nuclear missile 

When the North Korean leader Kim Jong Un celebrated the launch of a powerful new missile last month, he was surrounded by a group of top scientists and officials. State media did not identify the men, but they have all been seen with Kim before. 

These men — known by nicknames such as the "nuclear duo" and the "missile quartet" — have built an intercontinental ballistic missile that appears capable of hitting any city in the United States, a feat of physics and engineering that has  
tunned the world. 

At only 33, Kim has been ruthless about consolidating power, executing scores of senior officials, including his own uncle. But he has showered his regime's scientists with incentives and adulation, turning them into public heroes and symbols of national progress.