ART OF THE DEAL: U.S. Oil Vanishing From Chinese Tariffs Reveals America’s Clout. “China’s original plan to target U.S. crude came at an inopportune time for the country’s buyers. Sinopec’s trading unit, Unipec, was embroiled in a dispute with Saudi Arabia, saying the producer’s prices were costly and cutting purchases just as it was boosting American imports. Two months on, refiners were faced with the risk of supply disruptions from Iran to Venezuela and paying more to take advantage of booming U.S. output.”