South Korean President Moon Jae In has a daunting task ahead of him. When he meets with U.S. President Donald Trump on June 29 and 30, he will have to try to reconcile the differences between their administrations. Moon, who has been in office only since early May, is the last of the three main Northeast Asian leaders to meet with the U.S. president. Unlike Chinese President Xi Jinping and Japanese Prime Minister Shinzo Abe, moreover, the South Korean president is meeting Trump in Washington and not at the so-called "Winter White House," Mar-a-Lago. The change in venue may be due to the season, or to the public scrutiny that Trump has drawn for the expense of his trips to Florida. But some observers in South Korea see it as a sign that Washington places lower priority on its relationship with Seoul relative to its ties with Tokyo or Beijing....