The QRF security element posts up four-corner security around an objective site during a Quick Reaction Force drill, as part of Marine Expeditionary Force Exercise 2015 aboard Camp Pendleton, Calif., Feb. 22, 2015. Marines with 1st Law Enforcement Battalion employed a QRF to combat imminent “enemy threats” during MEFEX-15. - The QRF security element posts up four-corner security around an objective site during a Quick Reaction Force drill, as part of Marine Expeditionary Force Exercise 2015 aboard Camp Pendleton, Calif., Feb. 22, 2015. Marines with 1st Law Enforcement Battalion employed a QRF to combat imminent “enemy threats” during MEFEX-15.