U.S. Army Paratroopers with 2nd Battalion, 503rd Infantry Regiment, 173rd Airborne Brigade and Serbian Paratroopers come together to perform Sustained Airborne Training (SAT) during Exercise Double Eagle 2017 in Serbia on November 14, 2017. Exercise Double Eagle is a multi-national company-level airborne insertion exercise designed to enhance the relationship between the U.S. and Serbia and strengthen regional security.