Ali Soufan, Founder of The Soufan Center, participated in a Special Meeting of the Counter-Terrorism Committee on “Security Council Resolution 2396 (2017): Review of the Madrid Guiding Principles”. The United Nations Security Council Counter-Terrorism Committee held a Special Meeting to revise the Madrid Guiding Principles on foreign fighters. Adopted in 2015, the Madrid Guiding Principles consist of 35 practical tools to assist States in stemming the flow of foreign terrorist fighters (FTFs) to conflict zones. Since these principles were adopted three years ago, the flow of FTFs to conflict zones has decreased. However, as FTFs are returning to their home countries, relocating to other States, or to different conflict zones, a number of different challenges arise, including former foreign fighters’ possible re-engagement in terrorist activities.