Baghdad, Iraq—August 24, 2005: Manning checkpoints is an unpredictable, volatile task where every incoming vehicle symbolizes a possible death sentence. Vehicle-borne IED attacks against military and police checkpoints across the nation occur multiple times each month, leaving a slew of dead, wounded, and traumatized soldiers and civilians in their wake.

Sporadic ambushes, urban suicide bombings, and random IED placements continue to plague Iraqi Police and the US military, but this week’s crowning achievement by the insurgency comes by way of multiple ambushes on roadside checkpoints.

40 insurgents in civilian cars unleash a punishing attack against Iraqi Police operating checkpoints in several Baghdad neighborhoods. All at once, rocket-propelled grenades sear the air and grenades detonate, blowing to bits anything and everything in proximity. Furious machine gun fire fills the air. The simultaneous explosions happen in such swift coordination, the police initially believe a single car bomb has detonated.

After the devastating attack and the ensuing 90-minute battle, four police officers are dead and a total of 59 people lay wounded. Also killed in the violence are nine innocent civilians, still all-too-common victims of the insurgency. Just last month, 25 children playing near a military checkpoint were killed when a suicide bomber detonated his explosive-laden vehicle at the temporary roadblock.

Some checkpoints are permanent fixtures outside cities, but many are put into place in a matter of minutes. Soldiers and police are ever-conscious that signs and lights are sometimes hard to see, creating a harrowing, and possibly tragic, situation if civilians do not stop. In a 5-month period in 2003, 11 of 18 civilian deaths in the Baghdad area occurred at checkpoints. Improvements have been made, and the sheer number of checkpoints contributes to a better civilian understanding, but the fear of making a mistake has everyone on edge.

There is an enormous pressure—possibly greater than anyone will ever understand—on checkpoint soldiers. With every incoming vehicle, they have to make a series of split-second decisions, choices that determine the life or death of the vehicle’s occupants, and of their own men.

The insurgents know the inherent vulnerability that lies in conducting checkpoints: Stopping each vehicle and approaching its occupants is a painstaking process. Let a suspicious vehicle through and you could open the door for a suicide bomber; take too much time and you risk shifting attention away from your surroundings. Checkpoint operators are fully exposed, and there are countless ways to be attacked.

And in Baghdad, the insurgents give it all they’ve got.