There is no justification that allows a government to raise tariff levels based on immigration levels. To take such a step means that the United States has decided that it will no longer bound by international trade rules.  The early commentary on the Mexico decision has been nearly entirely focused on which companies in which sectors will be most at risk from an increase in tariffs by 5% on June 10, with additional increases monthly afterwards until every inbound product faces 25% tariffs by October 1.  Such a damage assessment is important for firms that suddenly awoke to find themselves in the front lines of a new trade conflict that they did not anticipate. But it misses the larger point—everyone is affected by this decision.  It is not just companies that ship goods from Mexico to the United States that should be paying attention.  If the US proceeds down this path, it is the end of the global trade regime that has given stability and lowered risks for an increasingly larger share of companies and consumers since the 1940s.