Donald Trump upended conventional trade policy in 2017, but there are critical deadlines in 2018 that will reveal the wisdom or calamity of his ways. While agriculture is one U.S. sector lamenting the direction that has been set, the sheer size of the American economy makes trade disruptions less impactful. China Washington laid the groundwork in 2017 for some major trade remedy actions against China in 2018. Some question whether Mr. Trump will really threaten the $600 billion trading relationship with the Middle Kingdom. American soybean growers certainly have much to fear, but others note that the U.S. is not alone in its criticism of Beijing’s mercantilist ways. The EU just issued a study on China’s “socialist market...