# Weatherhead Research Cluster on International Security ## expand\_more Much scholarly and public attention is paid these days to nonconventional security challenges like civil conflicts, terrorism, and human security more broadly. Our cluster aims to revive the academic study of traditional interstate security studies at Harvard. This, however, is not a return to ‘old’ security studies nor a reproduction of policy-focused security studies. We are interested in employing new theories and methodologies that are relevant to understanding understudied features in traditional interstate security. Our focus is on three novel research lines: **1. The psychology of diplomacy and decision making in real-world conditions** - How does collective decision making in foreign policy differ from individual decision making? - How do individual-level characteristics aggregate in groups? **2. The impact of social media on the speed and intensity of security dilemmas and crisis behavior** - Does social media speed up the intensity of security dilemmas between states? - What are the implications of social media for how states defend sovereignty? - How can governments maintain restraint during interstate military crises if their societies are engaged in large-scale social media conflict? **3. The implications of nuclear multipolarity, new technologies, and geography, under post-Cold War conditions** - How do perceptions of external threats interact with civil-military relations and organizational behavior to shape the ways in which nations handle nuclear weapons? - What lessons may be drawn from Cold War history? - How do multiple nuclear actors affect nuclear stability as an “emergent property”? The Weatherhead Research Cluster on International Security is chaired by Professors Iain Johnston, Joshua Kertzer, and Stephen Rosen. ### Related Links - [Funding: Weatherhead Research Clusters](https://wcfia.harvard.edu/funding/faculty/weatherhead-research-clusters) ## Administration [### Alastair Iain Johnston ](/people/alastair-iain-johnston) Faculty Associate. The Governor James Albert Noe and Linda Noe Laine Professor of China in World Affairs, Department of Government, Harvard University. Research interests: Socialization; identity, racialization, and security dilemmas; and China's international relations. ![Alastair Iain Johnston.](/sites/g/files/omnuum8891/files/styles/hwp_4_5__690x865/public/wcfia/files/johnston_alastair_iain.png?itok=llvSYLDi) [### Joshua D. Kertzer ](/people/joshua-d-kertzer) Faculty Associate (on leave 2025–2026). John Zwaanstra Professor of International Studies and of Government, Department of Government, Harvard University. **Research interests:** International security; US foreign policy; political psychology; and public opinion about foreign affairs. ![Josh Kertzer.](/sites/g/files/omnuum8891/files/styles/hwp_4_5__690x865/public/wcfia/files/kertzer_josh_1.jpg?itok=YeIjpvaY) [### Stephen Peter Rosen ](/people/stephen-peter-rosen) Faculty Associate (emeritus). Beton Michael Kaneb Professor of National Security and Military Affairs, Emeritus, Department of Government, Harvard University. Research interests: Nonrational aspects of strategic behavior; impact of social structures on military organizations; and technological change and the future of war. ![rosen_sp.jpg](/sites/g/files/omnuum8891/files/styles/hwp_4_5__690x865/public/wcfia/files/rosen_sp.jpg?itok=uSfI-vR7) [### Sarah Pollack ](/people/sarah-pollack) Coordinator of the Weatherhead Executive Office and Weatherhead Scholars Program. ![Sarah Pollack.](/sites/g/files/omnuum8891/files/styles/hwp_4_5__690x865/public/2025-06/pollack_sarah.jpeg?h=cd8821c2&itok=ifn-Ntes) ## Contact **Sarah Pollack** *Coordinator of the Executive Office and Weatherhead Scholars Program; Staff Assistant, Weatherhead Research Cluster on Business and Government.* 1737 Cambridge Street Room K230 Cambridge, MA 02138 p: (617) 495-8349 See also:- [ Research Clusters ](/content-types/research-clusters) - [ Past Research Clusters ](/content-types/past-research-clusters)