security studies rapidly developed within International Relations during the Cold War, and examples from the era can be considered to include the academic works of mid-20th century Realist political scientists such as Thomas Schellingand Henry Kissinger,whose works focused primarily on nuclear deterrence. While the field is mostly contained within Political Science and Public Policy programs, it is increasingly common to take an interdisciplinary approach that incorporates knowledge from the fields of History, Geography (stressing classical geopolitics), and Criminology