A siren wails, followed by the all-too-familiar giant voice. "This is the command post. Code Red is in effect. Stay down. I say again, Code Red. Stay down," the voice booms through loudspeakers to troops hunkered in tents piled high with sand bags.
The unmistakable thud of impacting rockets and mortars sent soldiers and airmen scurrying for cover four times on one recent day at this sprawling US base, one of the most heavily bombarded in Iraq.
The crescendo of attacks on this US logistical hub is a measure of the violence anticipated by commanders here during the transition of power to anIraqi government. It is especially significant in that Balad is slated to become a prime US military installation in Iraq as American forces consolidate and exit politically symbolic locations such as Baghdad International Airport, where 11 soldiers were wounded Wednesday after insurgents blasted the base with 10 mortar rounds.
"We are making Balad Airfield our primary hub in the region ... because we need to have the Baghdad International Airport revert to civilian control," Gen. John Abizaid said recently of the base, where some 17,000 US troops are now stationed.
The former Iraqi fighter base has one functioning 11,000-foot runway and hardened shelters that now house US jets and surveillance drones. Military engineers are busy repairing the control tower and a second runway, pouring concrete to expand aircraft parking space, and building housing for troops now living in tents.
Yet Balad also presents a big target. Persistent strikes show how difficult it is for US forces with superior technology to find the insurgents who orchestrate the barrages from Sunni Triangle back roads and villages.
Indeed, for the thousands of men and women serving at Camp Anaconda, the explosions have become so common that a day without them is oddly disturbing. "The unusual thing was once we went five whole days without an attack," says one Air Force officer, who heads to the shower wearing a helmet and flak vest.
Two service members were wounded last Friday as upwards of 16 rockets and mortar rounds impacted inside the heavily fortified camp. The previous week, a strike left four Americans dead, and wounded more than 20. One of those killed, Sgt. Arthur Mastrapa, was waiting for his flight home after a year in Iraq.
"We just hope it doesn't happen when we're all lathered up [in the shower]," says Air Force Capt. Shellie Russell, who like others puts a gloss of good humor on a grim day-to-day existence.
So far, aggressive US countermeasures have not halted the strikes, as insurgents grow cleverer in evading them by using devices such as timers, and launching coordinated attacks from multiple directions, officers here say.
Inside an old Iraqi aircraft bunker, Air Force Maj. John Erickson was using remote controls to fly an unmanned Predator surveillance drone back to the base last Friday afternoon when news of another attack crackled over the command post radio: "Alarm Red! Alarm Red!"
"We're going to start a new mission: Base defense," Major Erickson advised, pulling up the Predator's landing gear and ordering the drone's two 100-pound Hellfire missiles ready for launch.
Within seconds, Erickson was handed the coordinates. Zooming in on an overgrown area near a suspicious berm, he used the Predator's infrared cameras to scan for people or cars leaving the area.
The Predator, a $40 million experiment, is in high demand in both Iraq and Afghanistan, where several drones are airborne 24 hours a day. With a 50-foot wingspans, the light, insect-like, gray aircraft can inspect targets for hours. This time, though, the enemy proves invisible. "Something move!" says Airman Brandon Youngblood, manning the Hellfire missiles.
Meanwhile, more incoming rockets are exploding around the base. An Apache attack helicopter sweeps in as a platoon of ground troops from the base rolls up in five trucks to scour the area. They, too, come up empty handed. "You can see how hard it is to spot one or two guys with a tube," Erickson says.
Commanders at Balad expect the worst may be yet to come. "There's a big fight ahead," says Col. Blair Hansen, commander of the Balad-based 332nd Air Expeditionary Wing with 5,000 people throughout Iraq. Still, with the transition of power to Iraq's fledgling interim government, Colonel Hansen acknowledges that just how long the US can stay at Balad remains an open question. "Will we be here six months from now? Likely," he says. "Two years from now? Five years from now? The environment is very uncertain."