Joshua Dunn, 377th Civil Engineer Squadron firefighter, participates in exercise Global Thunder 20 where first responders responded to a simulated chemical, biological, radiological, nuclear and high–yield explosive emergency at Kirtland Air Force Base, N.M., Oct. 24, 2019. Global Thunder is a worldwide exercise that provides training opportunities for all of U.S. Strategic Command’s mission areas, tests joint and field training operations, and has a specific focus on nuclear readiness. (U.S. Air Force photo by Airman 1st Class Austin J. Prisbrey)