In an influential monograph, Snyder, Bruck, and Sapin (1954; see also Snyder et al. 2002) argued that people and process matter in international affairs and launched the study of foreign policy decision making. They contended that it is policy makers who perceive and interpret events and whose preferences become aggregated in the decision-making process that shape what governments and institutions do in the foreign policy arena. People affect the way that foreign policy problems are framed, the options that are considered, the choices that are made, and what gets implemented. To bolster their claims, Snyder and his associates brought research from cognitive, social, and organizational psychology to the attention of scholars interested in world politics. They then introduced the experiment as a potential methodological tool.

Because it remains difficult to gain access to policy makers and the policy-making process in real time, the experiment has become a tool for simulating “history” and for doing so under controlled conditions. It allows us to explore the causal relationships that occur between the nature of the people involved, the decision-making process, and the decisions that are made. In effect, experiments provide us with access to the temporal sequence that occurs during the decision-making process and help us study how the preferences policy makers bring to the process shape what happens both in terms of the nature of that process and the resulting decisions.