U.S. diplomat Joseph Yun likes to joke that his mother has a rule about Washington titles: the shorter it is, the more important the job. President? The most important. Vice President? Close.

So when Yun told his mother about his latest title – Special Representative for North Korea Policy and Deputy Assistant Secretary of State for Japan and Korea – she was hardly impressed, according to his retelling.

But here’s the truth: in a time when North Korea consistently remains at the top of our national security agenda, Yun’s job may be one of the most important in Washington.

That’s