5-28. Army forces may conduct large-scale combat operations in urban areas within the JOA or theater of operations. Currently more than 50 percent of the world’s population lives in urban areas, and this is likely to increase to 70 percent by 2050, making large-scale combat operations in cities likely. Commanders may conduct urban operations because they provide a tactical, political, or economic advantage, or when not doing so threatens the joint campaign. Army forces conduct large-scale combat operations in urban areas either as a specific, unique operation, or more typically, as one of a larger series of operations in a joint campaign. Urban operations focus on the threat to or within the urban area and allow other forces to conduct operations elsewhere. Conducting operations in dense urban terrain is complex and resource intensive. Due to the complexity of an urban environment, commanders must carefully arrange their forces and operations according to purpose, time, and space to accomplish the mission. In most urban operations, the terrain, the dense population, military forces, and unified action partners will further complicate this arrangement. (See FM 3-06 for an in depth discussion of operations in urban areas.)