Americans presented Chinese officials with intelligence on Russia’s troop buildup in hopes that President Xi Jinping would step in, but were repeatedly rebuffed. Over three months, senior Biden administration officials held half a dozen urgent meetings with top Chinese officials in which the Americans presented intelligence showing Russia’s troop buildup around Ukraine and beseeched the Chinese to tell Russia not to invade, according to U.S. officials.Each time, the Chinese officials, including the foreign minister and the ambassador to the United States, rebuffed the Americans, saying they did not think an invasion was in the works. After one diplomatic exchange in...