A new Army and Marine Corps urban warfare manual warns that inevitable big-city operations will be complicated as long-held U.S. advantages in technology and firepower may be of limited value and casualties among troops and the local population could be high.

Urban warfare is a virtual certainty, says Army Technical Publication ATP 3-06, which was released Dec. 7, replacing an October 2006 urban warfare guide. Fifty percent of the world’s population lives in urban areas, but this will grow to 70 percent by 2050, numbers the manual says makes “military operations in cities both inevitable and the norm.”

“Though casualties occur in all operations, commanders recognize the likelihood of more casualties during large-scale or high-intensity urban operations,” the manual says, advising commanders to make certain their superiors know if the casualty risk is high so the risk can be weighed against the objective.

The manual is aimed at commanders and leaders, trainers and educators, and soldiers to guide concepts and techniques for urban operations. It isn’t just about fighting. It is also a guide for disaster-relief and humanitarian operations, taking steps to prevent conflict by separating belligerents.

Operations in cities can require more resources—especially time and manpower—and have new complications, like military action causing major fires, chemical spills or the loss of water or electric services that would be disruptive to the lives of the local population. Relocating civilians might be required, the manual says.

The manual is available from the Army Publishing Directorate.