Overnight, Russia's ambassador to Turkey was assassinated by a police officer. And, in Germany, nine people are dead, and at least 50 are injured, after a truck ploughed into a crowd close to a Christmas market, in what is suspected to be a deliberate attack. US national security expert, Jamie Metzl, is a senior fellow of the Atlantic Council. He's served on the US National Security Council, State Department, Senate Foreign Relations Committee, as executive vice president of the Asia Society and with the United Nations in Cambodia. Jamie is also an author, commentator on international affairs, genetics, virtual reality and is a former US presidential advisor.