What accounts for the variation in violence against civilians perpetrated by combatants in conflict? Why do some individuals act violently against civilians, while others witness violence but do nothing to perpetuate or stop it, and still others renounce violence altogether? Why are some units noticeably more violent than others? And what accounts for temporal variations in violence and resistance? These are the primary questions I pose in my dissertation project, which studies patterns of political violence and resistance through a case study of Israeli soldiers in the second Palestinian Intifada, 2000-2005. While theories on sources of violence abound, both in political science and in social psychology, few studies attempt to evaluate these theories based on solid, disaggregated empirical evidence, often due to the difficulty of gathering data in the midst of violent conflict. Israel presents a unique case as soldiers are free to speak about their military experiences. It is therefore possible to study both violent acts against Palestinian civilians and acts of soldier resistance and refusal, at the individual and unit level. My dissertation draws on theories from political science, international relations, and social psychology to derive five sets of hypotheses that explain violent behavior against civilians. I will investigate the determinants of soldier violence and refusal to commit violence through an ethnographic study of Israeli combat soldiers, as well as through quantitative analysis of a database I will compile on violent events in the Second Intifada. By accessing the voice of perpetrators during violent conflict, I will gain insight into the sources of violence and resistance, and the processes through which they come about.