As video cameras have become cheaper, it's become possible to use build them into training areas and digitally record troops running through realistic combat exercises. This has provided a unique ability to capture, on video, troops making mistakes that would get them killed in combat. In the past, an NCO or officer had to be right there to catch the error, recognize it, and remember it. This didn't happen often enough. As a result, many troops made errors in training that got them killed in combat. No longer. The U.S. Army has built a 26 building urban combat training center that is covered by over 1200 cameras, many of which can see at night. Troops can be caught in the act, and later shown, bad moves. Moreover, instructors can review the tapes and detect patterns of bad moves, and change training programs to make sure the troops get it right before they go up against a situation featuring real bullets and booby traps. The $24 million MOUT (Military Operations on Urbanized Terrain) complex at Fort Polk, La. enables the army to see bad habits that have often been missed in the past, and develop new tactics with confidence that the troops will be using moves that have been carefully examined and work. It's always been possible to intensively train elite career troops to a high degree of effectiveness. But this is expensive and time consuming. Most infantry are in for only a few years and the only thing that works is teaching them drills that will, you hope, work. Now the drills can be refined and troops tested to make sure that it works. This generally unreported training advantage has made an enormous difference in the capabilities of American combat troops.