Firefighters with the Latvian National Armed Forces and Estonian Defense Forces use a fire hose to spray a simulated aircraft fire at Alpena Combat Readiness Training Center, Michigan, Aug. 12, 2021. The simulation was part of exercise Northern Strike 21-2, which is a National Guard Bureau-sponsored exercise that has brought together 5,100 participants from various states and countries at the National All-Domain Warfighting Center. (U.S. Air National Guard photo by Staff Sgt. Valentina Viglianco)