Defense chief tells Air Force graduates to be ready for war

U.S. Air Force Academy cadets toss their hats in the air as the Thunderbirds fly overhead during the cadets' graduation ceremony in Colorado Springs, Colo., on Wednesday, May 23, 2018. (Jerilee Bennett/The Gazette via AP)

Defense chief tells Air Force graduates to be ready for war

U.S. Air Force Academy cadets toss their hats in the air as the Thunderbirds fly overhead during the cadets' graduation ceremony in Colorado Springs, Colo., on Wednesday, May 23, 2018. (Jerilee Bennett/The Gazette via AP)