This document provides an overview and analysis of classical country-based trade theories and modern firm-based trade theories. It discusses theories such as Mercantilism, Absolute Advantage, Comparative Advantage, Heckscher-Ohlin theory, Product Life Cycle theory, New Trade Theory of Economies of Scale and First Mover Advantage, and National Competitive Advantage. It analyzes these theories and compares classical country-based theories with modern firm-based theories. The document also provides a case study on Toyota's global strategy applying several of these international trade theories.