Free trade refers to the absence of restrictions on international trade between two nations. As a commercial policy affecting international trade, free trade is the opposite of protectionism. Where protectionism calls for tariffs and duties on imports to "protect" a country's domestic producers, free trade is a policy of allowing imports and exports to flow freely between nations without any restrictions.

In the 18th century, Scottish economist Adam Smith (1723-1790) wrote The Wealth of Nations to explain the benefits of free trade. What he proposed has come to be called unilateral free trade. That is, he called on nations to unilaterally practice free trade by allowing unrestricted free access to their domestic markets. In addition, he recommended a nation neither hold back nor...