After days of speculation, North Korea says it test-fired a ballistic missile from a submarine in order to enhance its undersea capabilities. It’s the first such launch since 2016. This comes as the US, South Korea and Japan are meeting to discuss restarting talks with Pyongyang — talks that have been rebuffed by North Korea. Alarmed by the recent spate of test launches, the United Nations Security Council has also called an emergency meeting. The World’s Marco Werman speaks to Sue Mi Terry, a former intelligence analyst specializing in Korean affairs.