What is North Korea's end game with its nuclear program?
In our series, Issues That Matter, we take a closer look at the tensions between the U.S. and North Korea. The standoff is one of President Trump's biggest challenges overseas. Former CIA deputy director and CBS News senior national security contributor Michael Morell and New Yorker staff writer Evan Osnos, who traveled to North Korea on assignment, join "CBS This Morning" to discuss how Mr. Trump's rhetoric and mixed messages impact the situation, and Kim Jong Un's goals as he ramps up his country's nuclear arsenal.