President Trump’s sudden threat of US tariffs on Mexican imports escalates his immigration fight with Mexico, injecting potential chaos into economies on both sides of the border. Trump hopes tariffs will pressure Mexico into stepped up efforts to contain illegal border crossings, but how are such threats received in Mexico? Has Mexico in fact conceded to the “safe third country” agreement to avoid higher tariffs? What happens if tariffs just antagonize our neighbors to the south, whom we count on for collaboration on a number of critical issues? Is the US-Mexico relationship at a breaking point?