After reading this lesson i learning will be able to;  why nations trade with each other. Be familiar with the different theories explaining trade flows between nations. i can Understand why many economists believe that unrestricted free trade between nations will raise the economic welfare of countries that participate in a free trade system. Be familiar with the arguments of those who maintain that government can play a proactive role in promoting national competitive advantage in certain industries. i Understand the important implications that international trade theory holds for business practice.