On today's show:
- After North Korea detonated a nuclear weapon on Friday, the U.S. today sent two bombers to fly over ally South Korea in a show of force. We get the latest from Korean peninsula expert Bruce Cumings of the University of Chicago.
- In 122 A.D., the Roman Emperor Hadrian began work in Britannia on a wall to mark the boundaries of the Roman Empire and keep out “barbarians”. Historian John Schmidt has the story.