When Chinese President Xi Jinping meets US President Donald Trump at the White House on September 24, trade will be the most measurable front of their rivalry. Since the first Section 301 tariffs took effect in July 2018, US imports of Chinese technology hardware have fallen sharply. Rare earth magnets are the exception: Washington cannot easily replace them, which gives Beijing leverage as the one-year Busan truce nears its November 10 expiry.