President Trump calls tariff “the most beautiful word in the dictionary.” This refutes the orthodoxy of unilateral free trade championed for hundreds of years beginning with the 1776 “Wealth of Nations” author Adam Smith, widely known as the father of modern economics.

Yet economist Donald J. Boudreaux of the American Institute for Economic Research and former economics department chairman at George Mason University writes Smith offered four exceptions to the principle of unilateral free trade: “These exceptions are, in the order in which Smith took them up, protective tariffs for purposes of (1) national security; (2) ensuring that imports are taxed by the home government no less than the home government taxes domestically produced goods and services that compete with imports; (3) pressuring foreign governments to reduce their tariffs; and (4) ensuring that workers in protected industries are not all hit suddenly and unexpectedly with the need to find new jobs.”