The Valens Team

Daveed Gartenstein-Ross
Madeleine Blackman
Carolina Ponzeto
Tara Vassefi
Vivian Hagerty
Sarah Sheafer
Sandro Bejdic
Bryce Aspelund
Jonathan Prohov
Jacob Zenn
Al-Husein Madhany
Aaron Reese



Daveed Gartenstein-Ross is the Chief Executive Officer of Valens Global. His professional focus is on understanding how violent non-state actors (VNSAs) are transforming the world, and how states are in turn trying to adapt to this challenge. Gartenstein-Ross has specialized in jihadist movements, including undertaking detailed research into al-Qaeda, the Islamic State (ISIS), Ansar al-Sharia in Tunisia, Boko Haram, and ISIS’s Wilayat Sinai. He is also a Senior Fellow at the Foundation for Defense of Democracies, as well as a Fellow with Google’s Jigsaw, an Associate Fellow at the International Centre for Counter-Terrorism – The Hague, and an Adjunct Assistant Professor in Georgetown University’s Security Studies Program.

Known for his rigorous scholarship, and also putting ideas into action as a practitioner, Gartenstein-Ross is the author or volume editor of twenty-one books and monographs. He has published widely in the popular and academic press, including in The New York Times, The Washington Post, Foreign Affairs, Foreign Policy, The Atlantic, and Terrorism & Political Violence. He is also a member of the Editorial Board of the leading peer-reviewed journal Studies in Conflict & Terrorism. As a practitioner, some of Gartenstein-Ross’s recent projects have included:

  • delivering regular briefings and assessments to U.S. government agencies on such topics as ISIS’s European attack network, the implications of the failed coup in Turkey on counterterrorism efforts, and the strategic implications of the Libyan civil war;
  • organizing and facilitating a conference in Nigeria, as an EU-appointed Strategic Communication Expert, helping civil society activists understand militant groups’ use of social media and forge a strategic action plan for countering it;
  • mapping the online counter-ISIS narrative space for a leading tech firm designing a pilot project to divert users who may be susceptible to the jihadist group’s propaganda;
  • producing reports for major oil and gas firms interested in protecting their investments and personnel on the capabilities and future trajectory of militant groups based in Africa;
  • serving as a subject-matter consultant on militant groups during live hostage negotiations;
  • designing and delivering lectures and training for U.S. government personnel through such programs as the U.S. Army Corps of Engineer’s Individual Terrorism Awareness Course and the Naval Postgraduate School’s Leader Development and Education for Sustained Peace (LDESP) program;
  • designing and leading strategic simulations exploring the competition between VNSAs and state actors for major academic institutions such as Johns Hopkins University.

Gartenstein-Ross has testified on his areas of core competency before the U.S. House and Senate a dozen times, as well as before the Canadian House of Commons. He has also served as an expert witness in seven asylum cases. He is frequently a featured speaker at events and conferences throughout the globe, including delivering keynote speeches at the U.S. Army Special Operations Command Commander’s Conference, the University of Southern California’s National Center for Risk and Economic Analysis of Terrorism Events (CREATE), and the Global Futures Forum. Other venues where Gartenstein-Ross has spoken include the Royal United Services Institute (London), the Kazakhstan Institute for Strategic Studies (Kazakhstan), Uppsala University (Sweden), the National Defence College (Abu Dhabi), the North Atlantic Treaty Organization (NATO), the Minerva Research Initiative, and the Pulitzer Center on Crisis Reporting.

Gartenstein-Ross holds a Ph.D. in world politics from the Catholic University of America and a J.D. from the New York University School of Law. He can conduct research in five languages.

His e-mail address is, and he is active on Twitter as @DaveedGR.

Nathaniel Barr



Madeleine Blackman is the research manager at Valens Global, specializing in emerging threats within the MENA region. She supports the research team with projects concerning a range of issues related to violent non-state actors and their diverse theaters of operation.

Madeleine graduated cum laude from Georgetown University with dual degrees in government and psychology. She completed an honors thesis, to be published by the Journal of Peace Psychology in 2017, which examined correlations between personality traits and attraction to specific types of extremist propaganda. She worked for two years as a research assistant at Georgetown, focusing extensively on radicalization and issues related to countering violent extremism. Madeleine authored two entries in the Encyclopedia of Political Behavior, to be published by Sage Communications in 2017, and she coauthored a chapter entitled “Globalization and Terrorism: The Primacy of Collective Processes” in the 2nd edition of The Social Psychology of Good and Evil. Most recently she coauthored an article published in Terrorism Monitor with Nate Barr.

Madeleine Blackman



Tara Vassefi is a Special Advisor to Valens Global. At Valens, Tara supports business development, builds strategic partnerships, and provides expertise and input to company-wide research and analysis. Tara has had a range of experience from the government, non-profit, and private sectors. Tara started her career as Daveed Gartenstein-Ross’ research analyst focusing on terrorism, radicalization, and violent non-state actors. She went on to work in government for five years with the Leader Development and Education for Sustained Peace (LDESP) program where her responsibilities included everything from research and curriculum development to government contract writing and the bid-review process.

She was awarded the 2016 JD Distinguished Fellowship and is now a legal fellow working on MENA jurisprudence with the Video as Evidence Program at WITNESS, a human rights organization that collaborates with activists, human rights lawyers and international justice organizations to enhance the evidentiary value of video captured in the field. She is also a legal fellow with the Public Interest Law Network (PILnet).

She graduated cum laude from the American University Washington College of Law, received an M.A. in International Relations with Middle Eastern Studies from the University of St Andrews, and studied Arabic at Damascus University and the American University of Cairo. Tara is fluent in Farsi and skilled in French and Arabic.

Carolina Ponzeto



Carolina “Nina” Ponzeto is the Director of Business Operations at Valens Global. At Valens, Nina supports internal and external growth by overseeing day-to-day operations, talent acquisition, and client relationship management. Before joining Valens, Nina developed response, recovery, and business continuity exercises for private and public sector clients as an emergency management consultant at the Cadmus Group. Prior to that, she was a Brent Scowcroft fellow at the Aspen Strategy Group, focusing on client-management and logistics for their yearly Security Conference.

Nina has a Masters degree from Georgetown University in Security Studies, where she completed a thesis which examined the correlation between Dengue Fever outbreaks and political campaign outcomes in Brazil. She also graduated cum laude from the George Washington University with degrees in International Affairs, Psychology and a minor in Peace Studies. She is fluent in Portuguese and skilled in Spanish.

Vivian Hagerty



Vivian Hagerty is an analyst at Valens Global. In collaboration with Valens’ research team, Vivian works to provide innovative analysis and research on today’s most pressing security challenges. She specializes in violent non-state actors (VNSAs) in South Asia, as well as the relationships VNSAs form with one another globally. Being particularly interested in when and how these relationships fall apart, she has published on “terrorist divorce” and the ISIL/al-Qaeda split. In addition, Vivian has previous experience in government and NGOs, as well as language skills in French, German, and Turkish.

Vivian graduated magna cum laude from American University and is completing her Master’s degree in Security Studies at Georgetown University. As an undergrad, she majored in Homeland and National Security Studies with a concentration in terrorism and intelligence. She currently focuses on U.S. National Security Policy in Georgetown’s Security Studies Program.

Sarah Sheafer



Sarah Sheafer is an analyst at Valens Global. At Valens, Sarah specializes in jihadist organizations within MENA, South and Southeast Asia. Her expertise has also been applied to the nexus of cyberwarfare and terrorism where she published an article entitled “Hacking in the Name of ISIS: Should Americans Fear a Cyber Doomsday?” in the Georgetown Security Studies Review. Before Valens, Sarah worked as a research assistant for the Georgetown Security Studies Program and as an associate editor for the Georgetown Journal of International Affairs. She has also performed work for the National War College and the Middle East Institute, supporting research efforts related to foreign policy in the Middle East and the role of the military in statecraft.

Sarah holds a master’s degree from Georgetown University in security studies with a concentration in terrorism and substate violence. She graduated summa cum laude from the College of Charleston with degrees in political science and international studies. She has advanced proficiency in Modern Standard Arabic and expertise in Eastern Arabic.

Sandro Bejdic



Sandro Bejdic is a Research Fellow at Valens Global. Sandro moved from Brussels to Washington, D.C. in order to complete his dual master’s degree in international relations at the Université Libre de Bruxelles and the American University in Washington, D.C.

Sandro’s master thesis centered on the institutionalization of U.S. Special Operations Forces as a coercive measure in international politics, while his second academic capstone allowed him to participate in a practicum for the Defense Intelligence Agency. Infatuated with the city and its opportunities, he decided to stay and begin an internship at Valens Global after graduating in May 2017. His research at Valens focuses on Salafi jihadist groups throughout MENA, as well as domestic jihadist networks in Europe.

Sandro’s passion for literature and languages is reflected in his bachelor’s degree in linguistics and Germanic studies from Université Libre de Bruxelles. He conducts research in nine languages.

Bryce Aspelund



Bryce Aspelund is a Research Fellow at Valens Global. At Valens, Bryce tracks emerging trends and forecasts threats to national security by violent non-state actors (VNSAs). He specializes in providing analysis on Russia, Central Asia, and the countries of the former Soviet Union using his Russian language skills. Prior to his work at Valens, Bryce was a Ranger-qualified airborne infantryman with the 82nd Airborne Division who deployed to Afghanistan in support of Special Operations. He combines this operational experience with strategic-level studies to provide pragmatic, actionable intelligence to other national security practitioners.

Bryce graduated magna cum laude from the University of Texas at Austin with a degree in Government, a minor in Russian Language, and a certificate in Russian and Eastern European Studies. He has pursued fluency in the Russian language by attending the Middlebury College Intensive Summer Russian Program, as well as studying abroad in Moscow, Russia as a Fulbright Scholar. Additionally, Bryce was selected as a recipient of the Four Star Fellowship by The Jamestown Foundation, in its 11th Annual Terrorism Conference. He is currently completing his Master’s Degree in the Security Studies Program at Georgetown University, where he concentrates on Terrorism.

Jonathan Prohov



Jonathan Prohov is a Research Fellow at Valens Global. At Valens, he specializes in jihadist organizations in the MENA region. He has published articles on  ISIS and the illicit antiquities market, counterterrorism policy regarding foreign fighters, and on Hezbollah. Prior to Valens, Jonathan worked as a graduate research assistant at the Monterey Terrorism Research and Education Program (MonTREP) as well as a research assistant in the counterterrorism and intelligence program at the Washington Institute for Near East Policy. He has basic proficiency in Modern Standard Arabic.
Jonathan holds a master’s degree from the Middlebury Institute of International Studies in nonproliferation and terrorism studies. He graduated from the College of William and Mary with degrees in International Relations and Middle East Studies.
Jacob Zenn



Jacob Zenn is a Senior Consultant at Valens Global. He was component leader under European Union Technical Assistance to Nigeria’s Evolving Security Challenges (EUTANS) from 2014 to May 2016, and supported a CT Sahel project in Niger as part of the Instrument for Stability (IfS) of the EU. In 2015-2016 he provided analyses of Boko Haram’s organizational structure to the Swiss Embassy in Abuja, which supported negotiations that led to the release of 21 Chibok schoolgirls in October 2016. He is now on a consultant team as part of the Nigeria Stability and Reconciliation Programme (NSRP) drafting a Nigeria Policy Framework and National Action Plan on countering violent extremism (CVE) in Nigeria.

Zenn is a fellow on African and Eurasian Affairs at The Jamestown Foundation in Washington DC and a non-resident fellow at two think-tanks in Astana, Kazakhstan (Center for Security Programs) and Shanghai, China (Center of Shanghai Cooperation Organization Studies). Zenn is the author of more than 200 reports and articles on Nigeria, Central Asia and Southeast Asia and has spoken and published widely in the academic and popular press.

Zenn consults for clients who need to understand micro-level details about leadership, ideology, strategic communication, and operational trends of violent non-state actors (VNSAs)—and particularly those on the “geopolitical periphery” of the Middle East—as well as macro-level trends about how VNSAs in the 21st century are evolving in geographical, socio-cultural and historical context. He has provided briefings and lectures for a range of international actors, including United States Army, United Nations Counter-terrorism Executive Directorate, Canadian Special Forces, and UK Ministry of Defense, and he co-teaches a graduate-level course on VNSAs as an adjunct assistant professor in Georgetown University’s Security Studies Program. He has provided expert testimony to the U.S. Congress two times on Boko Haram and one time on Central Asian militancy.

Zenn holds a J.D. from Georgetown University Law Center, where he was a Global Law Scholar, and a Graduate Certificate in Chinese and American Affairs from Johns Hopkins SAIS-Nanjing University School of Advanced International Studies, where courses were taught in Mandarin. Zenn conducts research in more than 10 languages.

Al-Husein Madhany



Al-Husein Madhany, who serves as an Advisor at Valens Global, is a consummate connector and facilitator for diplomatic action.

Al-Husein currently reports to the Facebook CIO and serves as his executive business partner. Previously, he was the Executive Vice President of the One Nation Foundation based in Gig Harbor, Washington. Prior to moving out West, Al-Husein taught Arabic at Georgetown University and has published with the Brookings Institution on Islam, Muslim societies, and Social Media.

Al-Husein holds a BA from Wake Forest University and advanced degrees from Harvard, Georgetown, and the University of Chicago. He is a member of the Pacific Council on International Policy, was recently an Aspen Ideas Scholar, and has been a term member of the Council on Foreign Relations.

Al-Husein serves as a Senior Advisor (, the premier online destination to explore and experience the world’s beliefs. He also is Senior Consultant at the Duncan Group (, and offers expertise in four practice areas: recruitment, organizational consulting, coaching, and executive-level training for professional support staff.

Al-Husein lives in Silicon Valley with his wife and two children, where he enjoys running and teaching at the University of California, Silicon Valley extension campus. You can follow Al-Husein at

Aaron Reese



Aaron Reese is a Consultant at Valens Global. Aaron supports Valens’ research team across a variety of subjects, with a particular focus on security threats in the MENA region. Aaron specializes in open-source intelligence collection, and has a background in research on Egypt’s print media landscape. Aaron has been published in the journal Arab Media & Society; is quoted in media including Time, The New York Times, The Christian Science Monitor, and CityLab; and has appeared live Al-Jazeera English, TRT, and BBC Radio.

Prior to joining Valens, Aaron lived in Abu Dhabi where he worked as an analyst with the Delma Institute. He has previously served as the Deputy Research Director at the Institute for the Study of War and the Managing Editor of the Middle East Journal. Aaron received his Masters of Arts in Arab Studies from Georgetown University, and graduated from Rice University with a dual degree in Political Science and Religious Studies. He has also studied at the American University in Cairo, and is proficient in Arabic.

Aaron lives in Houston, TX with his wife and twins.