Staff Sgt. Christopher DeJesus, 89th Operations Support Squadron Survival, Evasion, Resistance, Escape specialist, demonstrates the proper technique of kneeing against his assistant, Senior Airman James Porter, 11th Civil Engineer Squadron water and fuels systems journeyman, during a combative training session Nov. 15 at the Joint Base Andrews S.E.R.E facility. Combative training provides Airmen with self defense knowledge in case they ever have to physically protect themselves from harm. (U.S. Air Force Photo/Senior Airman Perry Aston)