Reserve Marines with 4th Law Enforcement Battalion, Force Headquarters Group, Marine Forces Reserve, hold the line while simulating a riot, while training in a class on crowd control given by Slovenian and Serbian service members, during exercise Platinum Wolf 2016 at Peacekeeping Training Operations Center South Base in Bujanovac, Serbia, May 12, 2016. Platinum Wolf brings together service members from Bosnia, Bulgaria, Macedonia, Montenegro, Serbia, Slovenia, and the United States, it aims to build interoperability between the partnering nations and promote regional stability. (U.S. Marine Corps photo by Sgt. Sara Graham)