International Relations: A Simple Introduction offers an accessible guide to the central ideas and tools of international relations, with theory, empirical evidence, examples, and diagrams to support the analysis. Examine gains from trade theory, using the concepts of absolute efficiency, relative efficiency, opportunity cost, comparative advantage, and the terms of trade to learn why countries get involved with international trade. Explore trade liberalization, as the role of power and interdependence in states' liberalization policies is assessed with realist and liberal theories of...