Moon Jae-in, who took office last month, thinks his country needs a different strategy to contain its northern neighbor. South Korea’s new president, Moon Jae-in, will visit Washington next week. (Jung Yeon-Je/AFP/Getty Images) By Lally Weymouth June 20 Lally Weymouth is a senior associate editor for The Washington Post.SEOUL South Korea’s new president, Moon Jae-in, belong..