The Woodrow Wilson School offers a Doctor of Philosophy in Public Affairs in two research clusters: Security Studies; and Science, Technology and Environmental Policy (STEP). These clusters encompass serious policy challenges that need to be analyzed from multidisciplinary perspectives. Both clusters also include a substantial group of WWS faculty whose current research interests are central to the themes of the cluster. The purpose of the WWS doctoral program is to train top-quality researchers in these critical areas of public policy. Increasingly, the top analytical positions in government and nongovernmental organizations require doctoral training. It is also envisioned that some graduates will go on to tenure-track positions in academic institutions that value multidisciplinary training. The goal is to admit and enroll an incoming class of six students each year, with three in each cluster.