I learned the grim reality of urban combat in Fallujah

Twenty years ago, on what looked like a movie set built in the Quantico woods, I learned how to fight in a city. This faux city was called “MOUT Town.” MOUT—Military Operations in Urban Terrain—is U.S. military-speak for high-intensity urban combat, like what’s unfolding in Gaza. Tactically, MOUT was very different from the traditional combat we’d already studied in the Marine Corps. The urban battlefield was highly constricted; streets and buildings funneled us into close quarters with our enemy. Beyond every corner, window, or doorway lurked a potential ambush. Most notably, and adding a specific and complex layer to this type of warfare, civilians blended with adversaries, all played by instructors who ambushed us with paintball guns. Casualty rates in urban warfare far exceed those of other forms of combat, a fact reinforced by the dime-size paintball welts that covered my body by the end of MOUT week.

Less than a year later, in November 2004, I found myself leading a 46-man rifle platoon into Fallujah, in Iraq. This battle pitted 13,000 Marines and soldiers against a defending force of 4,000 al-Qaeda fighters. In staging areas outside the city, we drilled the urban tactics we’d learned in MOUT Town. Chief among those tactics was close-quarters battle, or CQB, a highly choreographed maneuver designed for hostage rescue in which a group of Marines enters a room and clears it of threats. These tactics look similar to what usually appears in movies featuring Navy SEALs or Delta Force operatives as they rescue hostages; it is a familiar, if violent, visual. The idea is to flood a room with so much speed and precision that you overwhelm a defending adversary; your enemy might be able to shoot the first man through the door, or even the........

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