June 29, 2007: The U.S. Army is trying to expand its training areas from the current seven million acres, to nearly 12 million acres. The additional acreage would be added to the some of the existing 102 training areas. Although the Department of Defense has spent over a billion dollars recently building urban training areas, even in Iraq and Afghanistan, a lot of the operations are still in wide open spaces. The main need for more space is the longer range of weapons, and the longer reach of sensors and communications systems. The area that a brigade of 4,000 troops can operate over has increased steadily over the last two centuries. Two centuries ago, you had nearly 5,000 troops per square kilometer of battlefield. The declined to 3,900 150 years ago, to 404 in World War I, 36 in World War II, 2.34 during the 1991 Gulf war, and today, it's down to less than two per square kilometer. Without sufficient space, modern combat units cannot realistically practice for war. Without that practice, more troops get killed the first time they do it for real, while being shot at.