A virtual workshop held on March 8-11, 2021, featuring a variety of distinguished US and Partner-Nation panelists from government, defense, academia, think-tanks, non-governmental organizations, and private industry to discuss whole-of-society matters that influence populations and affect legitimacy in the era of Great Power Competition. Topics include social media and big data influences, political warfare, China’s military modernization as it applies to gray zone activities, the recently released US Defense Department’s Irregular Warfare (IW) Annex, security cooperation and partner engagements in areas short of conflict, and other subjects of strategic interest.