Gaza warfare shows 'nasty' face of urban combat

"No commander wants to be in this position. No one likes being drawn into a fight in a city," said retired Gen. Donn Starry, who served in several commands involved in preparing U.S. Army combat strategies.

The Israeli government said its troops will stay in the Palestinian territory for now, despite the cease-fire. The longer the stay, Starry said, the greater the strain on maintaining the force.

Supply lines for food and fuel are notoriously difficult to keep intact in urban settings, where enemy forces can knock out roads or target transport vehicles. During the Cold War, Soviet generals often held war games specifically on ways to disrupt Allied supply routes into key European cities, said Starry.

"The whole city environment is a major problem from a military standpoint," Starry said. "You really have to move house by house, clearing it and holding it. That takes a lot of troops and coordination. There is really nothing easy about fighting in a city."