To South Koreans weary of the political polarization that led briefly to martial law, President Lee Jae Myung is showing a more human touch than his predecessor. But his biggest challenges lie ahead.

South Korea’s new liberal president, Lee Jae-myung, said Friday he plans to revive a 2018 military agreement with North Korea designed to ease border...

To South Koreans weary of the political polarization that led briefly to martial law, President Lee Jae Myung is showing a more human touch than his predecessor. But his biggest…