Gen. Stan McChrystal Sees Parallels Between Jan. 6 & Nazis

As the world grapples with the humanitarian fallout in Afghanistan, former four-star U.S. General Stanley McChrystal is watching it unfold knowing all too well what's on the line. McChrystal was the Commander of American and coalition forces in Afghanistan. He drew on this experience in his new book, "Risk: A User's Guide." He joins Walter Isaacson to discuss the major global threats.