Lt. Gen. John Kelly will soon become the new four-star commander at U.S. Southern Command, a post that will require him to oversee the fight against drug trafficking, natural disasters, humanitarian crises and cyber warfare in central and South America. As the Long War Journal points out, Kelly delivered a powerful 30-minute speech on Tuesday to the American Legion National Convention in Indianapolis. He addresses the extremist nature of the threat the U.S. faces from terrorists and how difficult it is for a family to deal with the loss of a loved one in a war zone — something he…