The power-and-conflict definition encompasses all governmental decisions and actions and also decisions and actions that occur outside of the government purview but that are nonetheless intensely political. Democracy is a governing structure rather than a system to promote a right or left agenda. Comparative politics is the domain of scholars who study domestic politics mostly outside of the United States. Political systems range from communism on the far Left to fascism on the far Right. International studies programs were initially housed in political science departments, and for good reason. One of the most intractable questions for politicians, diplomats, and political scientists today is what constitutes a legitimate state. The chapter provides information on two of the most important theories of international politics: realism and idealism. The body of theory known as liberalism today went by the term idealism for most of the twentieth century. Realism as an international theory is quite distinct from realism in everyday English parlance.