Just over two weeks before President Donald Trump is due to meet his counterpart Xi Jinping in Beijing, Chinese uncertainty over the US leader’s goals and the impact of the Iran war hangs over the highly anticipated state visit. Trump’s trip, his first to China in his second term, is aimed at sealing a trade war truce the two leaders shook hands on when they met in South Korea in October. But for Beijing, which likes to carefully choreograph such events to avoid any possibility of embarrassme...