Operation Freedom's Sentinel (OFS) was the official name used by the U.S. government for the mission succeeding Operation Enduring Freedom (OEF) in continuation of the War in Afghanistan as part of the larger Global War on Terrorism. Operation Freedom's Sentinel is part of the NATO-led Resolute Support Mission, which began on January 1, 2015. OFS had two components: counterterrorism and working with allies as part of Resolute Support.