While on his way to the historic summit meeting with Kim Jong-un of North Korea, President Trump attacked other world leaders by refusing to endorse a joint statement of the Group of 7 nations, which had just met in Canada. Why is the president picking fights with America’s closest allies and embracing its longtime opponents? Guest: Mark Landler, a White House correspondent for The New York Times, who is reporting from Singapore on the talks between Mr. Trump and Mr. Kim. For more information on today’s episode, visit nytimes.com/thedaily.