U.S. Army Lt. Col. Michael Zernickow addresses Soldiers assigned to Alpha Troop, 6th Squadron, 4th Cavalry Regiment, Combined Task Force Delta, about their exemplary execution of retrograde operations at Forward Operating Base Kunduz, in Kunduz Province, Afghanistan, Aug. 2, 2013. Alpha Troop closed its second base, after shutting down Combat Outpost Shir Khan in the span of 17 days. (U.S. Army photo by 1st Lt. Philip Back/Released)