Over the past week, the US Air Force has pulled all its strategic bombers back to the continental United States. That means there will no longer be bombers based, for example, in Guam, where they have been for 16 years, to deter China and North Korea. The World’s host Marco Werman speaks with Jon Wolfsthal, who served as senior director for nonproliferation and arms Control on the National Security Council under President Barack Obama. He’s now senior adviser to the Global Zero movement to eliminate nuclear weapons.