51st FW conducts ACE operations with ROKAF, military partners
U.S. Air Force Senior Airman Cooper Hartzos, 51st Maintenance Squadron fuel systems maintainer, receives a buddy check during a simulated Alarm Black scenario as part of Freedom Shield 25 at Suwon Republic of Korea Air Base, March 11, 2025. The five MOPP levels–MOPP 0 through MOPP 4–adjust protection measures against chemical, biological, radiological, nuclear, and explosive threats, like attack signal warnings. A core training objective of FS25 is de-escalation and implementation of Armistice mechanisms to prevent conflict. (U.S. Air Force photo by Senior Airman Sabrina Fuller-Judd)