Rick Klein, kneeling, self-defense trainer, explains to Team Mildenhall women how to disarm an attacker after escaping from a knife attack Feb. 4, 2014, at the Northside Fitness Center on RAF Mildenhall, England. Klein, a former police officer, assists Linda Vu, women’s self-defense trainer, by acting as an attacker in several scenarios during Vu’s self-defense seminars. By substituting an attacker with himself, Klein allowed Team Mildenhall women to practice real-world techniques in a controlled environment. (U.S. Air Force photo by Airman 1st Class Preston Webb/Released)