Having introduced the global drama in chapter 1 and reviewed its history in chapter 2, it is time to turn our attention to what drives the action on the world stage. Much like the plot of a play, the course of world politics is the story of the motivations and calculations of the actors and how they put them into action. Because states have long been and remain the most powerful actors on the world stage, our focus here will be on how states make and carry out foreign policy. Most of what occurs in world politics is a dynamic story of states taking actions and other states reacting to them, either directly or indirectly through international organizations. States are certainly not the only global actors, though, and the roles and decision-making processes of individuals (such as Osama bin Laden), transitional groups (such as Greenpeace), and international organizations (such as the UN) are taken up in other chapters.

The question is, where to focus our study of world politics. Is it most fruitful to study the nature of the world (system-level analysis), to study how countries make foreign policy (state-level analysis), or to study people as individuals or as a species (individual-level analysis)? The best answer is to understand all three levels. Below is a brief review of each level.

System-level analysis is a "top-down" approach to studying world politics. It begins with the view that countries and other international actors operate in a global social-economic-political-geographic environment and that the specific characteristics of the system help determine the pattern of interaction among the actors. Systems analysts believe that any system operates in somewhat predictable ways--that there are behavioral tendencies that the actor countries usually follow. Although each of us has free will, each of us is also part of many overlapping systems that influence our behavior and make it reasonably, although far from perfectly, predictable. These systems range from very local ones, such as your family and school, to much larger systems, such as your country and the world. Whatever its size, though, how a political system operates is based on four factors: structural characteristics, power relationships, economic realities, and norms.

State-level analysis, a second approach to understanding world politics, emphasizes the national states and their internal processes as the primary determinants of the course of world affairs. As such, this approach focuses on midrange factors that are less general than the macroanalysis of the international system but less individualistic than the microanalytical focus of human-level analysis. How well do you understand the roles of various actors, such as bureaucracies, legislatures, or interest groups, in making foreign policy? How do you feel about our government's foreign policy?

Individual-level of analysis focuses on human actors on the world stage. This approach begins by identifying the characteristics of the complex process of human decision making, which includes gathering information, analyzing that information, establishing goals, pondering options, and making policy choices. The human role in the world drama can be addressed from three different perspectives: human nature, organizational behavior, and idiosyncratic behavior. Human nature involves the way in which fundamental human characteristics affect decisions. Organizational behavior looks at how humans interact within organized settings, such as a decision-making group. Idiosyncratic behavior explores how the peculiarities of individual decision makers affect foreign policy.