President Trump’s announcement that he will impose 25 percent tariffs on Canada and Mexico starting tomorrow eclipsed concerns about South American weather and sent much of the agricultural futures complex into the red on Friday. Both countries will retaliate with Canada saying it will be on a dollar-for-dollar basis. One calculation suggests that retaliation by Canada and Mexico could reduce U.S. agricultural exports by up to $30 billion per year. Industry reactions were more muted than would ordinarily be expected for several reasons:

Tariffs are viewed as just Trump’s approach to statecraft for extracting actions or concessions. They are not supposed to last long. Trump aides are said to be looking at several offramps to avo...