A Croatian soldier hides in a concealed defensive position in a situational training lane during Immediate Response 15 in Slunj, Croatia, Sept. 13, 2015. Immediate Response 15 is a multinational, brigade-level, command post exercise utilizing computer-assisted simulations and field training exercises in Croatia and Slovenia. The exercises and simulations are designed to enhance regional stability, strengthen partner capacity, and improve interoperability. U.S. Army photo by Sgt. 1st Class Caleb Barrieau