Eugene Rumer, Director of Russia and Eurasia Program, Carnegie Endowment for International Peace. He previously served as the National Intelligence Officer for Russia and Eurasia from 2010-2014.
Roy Godson, Professor of Government Emeritus at Georgetown University. From 1993-2015, he also served as President of the National Strategy Information Center.
Clint Watts, Senior Fellow, Foreign Policy Research Institute Program on National Security
*Other witnesses may be added
Kevin Mandia, Chief Executive Officer, FireEye
General (Ret.) Keith Alexander, Chief Executive Officer and President, IronNet Cybersecurity. He previously served as Director of the National Security Agency and Chief of the Central Security Service.