Xi Jinping must always know that the United States is not weak or open to appeasing him. But the new 10% U.S. tariffs announced on $300 billion in Chinese goods by President Trump on Thursday carry significant risks, in addition to their potential rewards.

Until Thursday, China was increasingly confident of Trump’s declining confidence in his ability to force a deal. The Chinese are exceptionally astute about U.S. politics and sensitive to the electoral considerations influencing Trump’s management of the economy. And of course, the Chinese president has little regard for domestic opinion.