Urban operations are among the most difficult and challenging missions a BCT can undertake. Most UO are planned and controlled at division or corps level but executed by BCTs. The unified action environment of UO enables and enhances the capabilities of the BCT to plan, prepare, and execute offensive, defensive, and stability operations. Urban operations are Infantry-centric combined arms operations that capitalize on the adaptive and invative leaders at the squad, platoon, and company level. Combined arms is the synchronized and simultaneous application of the elements of combat power to achieve an effect greater than if each element of combat power was used separately or sequentially. The eight elements of combat power are leadership, information, movement and maneuver, intelligence, fires, sustainment, mission command, and protection. Leadership and information are applied through, and multiply the effects of, the other six elements of combat power. These six-movement and maneuver, intelligence, fires, sustainment, mission command, and protection-are collectively described as the warfighting functions. (See FM 3-0 for details.) The BCT is the Army's largest fixed combined arms organization and the primary close combat force. A key component in UO is the inherent ability of the BCT to tailor its force to meet the requirements of the urban environment. This introduction provides an overview of UO considerations that shape the subsequent discussions of operations at BCT and below.