“Sometimes you have to walk,” President Donald Trump said on Thursday at an afternoon press conference in Hanoi after his second summit with North Korea’s Kim Jong Un collapsed abruptly without an agreement. Trump explained publicly that Kim offered to dismantle his country’s most important nuclear facility if the United States lifted sanctions against the nation. According to Trump, Kim would not commit to dismantling other elements of North Korea’s weapons program, causing negotiations to collapse. “Basically they wanted the sanctions lifted in their entirety, but we couldn’t do that,” Trump said. Joining us for analysis of where U.S.-North Korean relations stand is Bruce Cumings, a professor of history at the University of Chicago and author of the books Parallax Visions: Making Sense of American-East Asian Relations at the End of the Century,The Korean War: A History and North Korea: Another Country.