US Air Force STAFF Sergeant Anthony Bechtold, Air Force Special Operations Command, tiredly stands down after a simulated chemical attack during the combat rifle competition at Lackland Air Force Base, Texas, during DEFENDER CHALLENGE 2000. Defender Challenge is the annual Air Force wide competition sponsored by Air Force Security Forces. This competition showcases the talents and capabilities of 13 international Security Forces teams in seven physical fitness, base defense and policing skills over six days