The Hon. John Tien is a distinguished external fellow at the Georgia Tech Strategic Energy Institute and the Georgia Tech Research Institute. He is also a distinguished professor of the practice in both the Sam Nunn School of International Affairs and the School of Cybersecurity and Privacy and a senior fellow at the Belfer Center for Science and International Affairs at the Harvard Kennedy School. 

Before joining Georgia Tech, Tien was deputy secretary of the U.S. Department of Homeland Security (DHS) from 2021 to 2023. In that role, he was the DHS chief operating officer, overseeing a budget of $105 billion and facilities in all 50 U.S. states and all territories as well as more than 3,000 personnel stationed overseas in more than 75 countries. 

Alongside the secretary of Homeland Security, Deputy Secretary Tien led the policy development, operational oversight, and risk management of the department’s statutory mission areas and subordinate agencies, including cybersecurity and protection of America’s critical physical and cyber infrastructure; disaster preparedness and recovery; supply chain optimization, border security, and free and fair trade; air, pipeline, and rail security; maritime physical and cyber security; citizenship and immigration services; protection of senior officials and safeguarding the U.S. financial system; and counter-narcotics production and trafficking. 

In his broader policy administration role, Deputy Secretary Tien served as a member of the National Security Council’s Deputies Committee, the board of the National Counterterrorism Center, and the President’s Management Council. 

Upon his retirement from DHS in 2023, he was awarded two of DHS’ highest civilian awards: the DHS Distinguished Service Medal, and the United States Coast Guard Distinguished Public Service Medal. 

Tien previously served in the Obama administration as a National Security Council (NSC) senior director for Afghanistan and Pakistan, the Bush administration as an NSC director for Iraq, and the Clinton administration as a White House Fellow for the United States Trade Representative. 

From 2011 to 2021, he held various senior leadership positions at Citigroup as a managing director in their Citi Retail Services and Global Consumer Bank organizations. Before Citigroup, he was a U.S. Army officer, retiring at the rank of colonel. His Army career included commanding an 1,100-soldier armored task force in combat in Iraq, serving overseas for nearly a decade, and teaching political science at West Point. Col. Tien’s military awards and decorations include the Bronze Star Medal, Combat Action Badge, and Valorous Unit Award. 

Tien is now serving on the corporate board of directors for Union Pacific Railroad, on the Carter Presidential Center’s Board of Councilors, and as a founding board member of the Avalon Action Alliance, a nonprofit focused on nationally scaling proven healthcare programs to help heal veterans and first responders who struggle with depression, PTSD, and traumatic brain injury. He is also an executive partner and ambassador for the Master’s in Business for Veterans program at Emory University’s Goizueta Business School. 

Tien holds a B.S. in civil engineering from the United States Military Academy at West Point and an M.A. in philosophy, politics, and economics from Oxford University, where he was a Rhodes Scholar. He is a life member of the Council on Foreign Relations. He lives with his wife Tracy in Atlanta and volunteers with and supports numerous local civic institutions including the High Museum of Art.

Vicki L. Birchfield is a Professor in The Sam Nunn School of International Affairs at Georgia Tech, Co-Director of the Center for European and Transatlantic Studies and Director of the study abroad program on the European Union and Transatlantic Relations. Dr. Birchfield received a DES from the Graduate Institute of International Studies from the University of Geneva, Switzerland (1993) and a Ph.D. in Political Science from the University of Georgia (2000). She is the author of Income Inequality in Capitalist Democracies: The Interplay of Values and Institutions(Penn State University Press 2008), Triangular Diplomacy among the United States, The European Union, and The Russian Federation: Responses to the Crisis in Ukraine (Palgrave Macmillan 2017) co-edited with Alsadair Young, Reporting at the Southern Borders: Journalism and Public Debates in the US and the EU co-edited with Giovanna Dell'Orto (Routledge 2014) and Toward a Common EU Energy Policy: Problems, Progress, and Prospects(Palgrave Macmillan 2011) co-edited with John S. Duffield. She has published articles in International Studies Quarterly, European Journal of Political Research, the Review of International Studies, Journal of European Public Policy, British Journal of Politics and International Relations, Globalizations, and the Review of International Political Economy. Her research and teaching specializations are European politics, the European Union, comparative politics, and international political economy. Other research and intellectual interests include the interplay of capitalism and democracy, social movements and the politics of globalization, and transatlantic relations. She has been a visiting scholar at Sciences Po, Paris and the University of Bordeaux and in 2012 was bestowed the honor of “Chevalier dans l’Ordre National du Mérite” (Knight in the National Order of Merit) by the French government.

Dr. Belton is an Associate Professor and Director of Undergraduate Programs in the School of Economics. Professor Belton’s initial training and research focus was on issues of monetary policy and how policy design and implementation impacts the cyclical behavior of the macro-economy. Currently, Professor Belton is involved in multidisciplinary analysis which examines the impact of political, cultural, and economic institutions on downstream outcomes of income distribution, business development, and social behavior. This research brings together issues of public policy, international affairs and economics to examine and developed much more broad theories of economic, political, and social development across ethnic groups and nation-states.

Ellen is Director of the Master of Science in Urban Design degree, an authority on sustainable suburban redevelopment, and a leading urbanist. Author of over 100 articles, she is co-author with June Williamson of the retrofitting suburbia book series documenting successful retrofits of aging big box stores, malls, and office parks into healthier and more sustainable places. Retrofitting Suburbia: Urban Design Solutions for Redesigning Suburbs, (Wiley, 2009, 2011) received a PROSE award as the best architecture and urban planning book of 2009 and has been featured in The New York Times, Time Magazine, Harvard Business Review, NPR, PBS, TED and other prominent venues. Case Studies in Retrofitting Suburbia: Urban Design Strategies for Urgent Challenges (Wiley, 2020) expands on the first book examining how new retrofits are helping communities disrupt automobile dependence, improve public health, support an aging population, leverage social capital for equity, compete for jobs, and add water and energy resilience. 

Ellen serves on several national boards and committees, is former Chair of the Board of the Congress for the New Urbanism, lectures widely and conducts community workshops. In both her teaching and research she focuses on helping communities address new challenges that they were never designed for – whether that’s through her unique database of successful suburban retrofits or studio classes on anticipating autonomous vehicles, coping with climate change or suburban blight. She taught at UVA and MIT before joining Georgia Tech as Architecture Program Director from 2000-2009.