Only on the "CBS This Morning" podcast, "CBS This Morning" co-host Norah O'Donnell talks with retired Navy Adm. James Winnefeld, Jr. and CBS News North Korea Consultant Robert Carlin about expectations ahead of President Trump's highly-anticipated second summit with North Korean leader Kim Jong Un. Winnefeld, former vice chairman of the Joint Chiefs of Staff under the Obama administration, and Carlin, former Senior Policy Advisor at the Korean Peninsula Energy Development Organization, discuss what both Trump and Kim have at stake going into the meeting and possible concessions they could make in order reach some kind of agreement regarding denuclearization.