Only on the "CBS This Morning" podcast, former Secretary of Defense James Mattis joins "60 Minutes" correspondent John Dickerson to discuss his new book, "Call Sign Chaos: Learning to Lead." The retired four-star Marine Corps general shares what it takes to become a successful leader ? from constructing the right team to building trust and creating a feedback loop. He tells Dickerson how his goal in the military had been to bring a little controlled chaos and disruption by challenging assumptions. Having served as President Trump's first secretary of defense, Mattis says a unique strength of America is its alliances and divisiveness threatens its democracy.