AUSA 2017 Opening Ceremony Soldiers assigned to the 3rd U.S. Infantry Regiment -- The Old Guard -- perform during the opening ceremony of the Association of the United States Army's annual meeting and exposition in Washington, Oct. 9, 2017. In the keynote address, Defense Secretary Jim Mattis said U.S. military is adapting to remain the most lethal joint force on the planet and to respond to evolving global security challenges. Army photo by Spc. Gabriel Silva SHARE IMAGE: Download Image: Full Size (0.66 MB) Tags: Opening Ceremony, 2017, Perform, old guard, ausa, 3d us infantry regiment Photo By: Spc. Gabriel Silva VIRIN: 171009-A-OA805-029.JPG Photo Gallery