World War II is an enormous topic,

World War II is an enormous topic, as is Operation Overlord. Therefore, this chapter will look primarily at a narrow slice of how some of the unorthodox activities coincided with the ground attack between May-September 1944. It will concern itself with some of the planning considerations concerning German interior lines. It will look at the challenge of gaining access to the deep maneuver areas—getting behind enemy lines. The study will take particular note of how combinations were a key feature of the Allied fight. This includes combinations of air bombing and ground sabotage, combinations of conventional force movement and unconventional force screening, and combinations of intelligence gathered from military intelligence and indigenous populations in deep areas and close areas.1