"As the forward deployed expeditionary element of United States military power, the United States Marine Corps (USMC) must be prepared to react quickly and effectively in the most unconventional of theaters. Given this unique war-fighting mission, the Marine Corps has had much experience throughout its history operating in urban environments. In this decade alone, Marines have deployed in several major peacekeeping operations; all have required a concentration of force in major urban centers. Operations in Somalia, Haiti, and Bosnia have proven that military operations on urbanized terrain (MOUT) are complex and challenging. Preparing for the demands of urban operations requires continual innovations in strategy, operations, tactics, and technology. In the future, Marine will face urban environment situations where different categories and activities will be conducted concurrently. Missions such as humanitarian assistance operations; peace operations; and full-scale, high-intensity combat may occur simultaneously within three city blocks. The Commandant of the Marine Corps has labeled this concept the 'three city block war.' Integrating and coordinating these varying missions- each of which has its own operational characteristics- will challenge Marines to use their skill and determination in imaginative ways. The presence of large numbers of noncombatants and the potential difficulty in distinguishing noncombatants from hostile forces will further complicate the task of operating in the urban environment. The Marine Corps has recognized these challenges and is staging URBAN WARRIOR exercises to test new tactics and equipment designed to make the USMC the leading U.S. force in MOUT."