What are the causes of war, how do we deter war, and what are some of the ways of war? We will address each of these issues. After briefly discussing deterrence theory, we will discuss the causes of war by focusing on individual, state, and international levels of analysis. Our substantive focus will range from WWI to Iraq, and will include ethnic conflicts and counter-insurgencies. We will then turn our attention to the effect of nuclear weapons on war and to the theory and practice of deterrence. We will discuss the spread of nuclear weapons, terrorism, chemical and biological weapons, and some problems with intelligence assessments. The course concludes with a discussion of morality and war, economic sanctions, and the future of warfare. The objective of this course is to familiarize students with deterrence theory, with different theoretical approaches to the causes of war, and to provide some background in a few substantive areas of international security.