He was certain it was an IED (improvised explosive device, the weapon of choice for those resisting the American occupation) and even though nobody else in the Command Group had seen it, he'd hounded his superior officers until they'd agreed to let him take a patrol back to investigate.

As a result, I'm in a convoy with Sgt. Allen and a squad from 1st Platoon, Charlie Company from the Engineers Battalion, leaving the base to locate the tin. It's night and a sandstorm is coming on, the wind whipping the flour-fine sand into our faces.

As we roar along, everything by the side of the road looks menacing. The men of 4th Infantry Division have been plagued by IEDs, 18 of which have been discovered in the last 10 days. Some are pressure-detonated, most are remotely set off, sometimes in series. They can be disguised in a plastic bag, or set in a chunk of concrete. Hooked up to a car battery with long wires they're sometimes detonated with a hole-punch, the wires welded to the handles.

IEDs can be deadly enough to kill the occupants of a Bradley, but it's the humvees, the bread-and-butter of American patrols, which are especially vulnerable.

Allen recognizes the stretch of road where he saw the tin; we actually roll right by it when the 113 rattles to a bone-jarring halt, spotlights trained on the glistening metal box. Two more of the massive tracked vehicles block off the road from both directions and the Explosives and Ordinance Disposal Team is called up from the rear. The EOD team consists of just two men, Staff Sergeant Richard Asberry and his assistant, who rotate with other teams between the half-dozen bases in Tikrit.

Asberry walks up to the tin and cautiously lifts up the lid to peer inside. He's pretty sure it's an IED, so he retreats to his small armored truck to suit up and collect some of the gear that will help him determine the makeup of the bomb.

With practiced speed, the two men maneuver the weird lobster-like suit, which weighs close to 100 pounds, onto Asberry's body. Asberry allows that the suit would "help" if the bomb went off, but no one thinks it would save his life if he were directly in front of a blast.

Asberry shuffles off into the darkness while we wait. I can see him in the far reaches of the light, casting off bits and pieces from the bomb. At last he returns and his assistant pulls his suit off his sweat-drenched body. The various top-secret anti-bomb devices hadn't been of much use. Asberry had simply dismantled the IED with his hands.

We go up to the bomb, and beside the empty tin are several pounds of carefully cut angle-iron pieces, chunks of PE4, which is a Russian plastic explosive, and bars of TNT. The bomb had not yet had the fuse in place. Presumably someone would have shown up tonight to finish the job.

An hour has passed since the beginning of the operation, and traffic is severely backed up in both directions. The team abandons the idea of ambushing the saboteurs. Instead, 1st Platoon scouts fan out over the area looking for a likely detonation spot, and find a second IED.

This is Asberry's 14th IED disposal and he's due to rotate out soon. Another EOD man was recently killed at his work. It's hard to believe that anyone would want this job, but Asberry says he loves what he does. Admission to the seven-month-long school to qualify as an assistant is highly competitive.

Most of the soldiers of the 299 Engineers Battalion in Tikrit are interested in explosives. They do a lot of blowing up weapons caches around here, ranging from small arms to huge surface-to-air missiles and even jets, which have been found wrapped and buried underground, usually hastily and shallowly.

One soldier tells me how, when his father discovered him playing with bottle rockets as a child, he took them away, telling him he could have them back if he could make a box of matches explode. So he designed a closely fitting sealed plastic container that would allow one match to enter as the fuse, and blew it up. He got his fireworks back.

The 299 Battalion is stationed in a dramatic series of huge buildings that were only half-finished before the war halted the construction. With their soaring arches and exposed brick surfaces, they look like Crusader castles, especially dramatic at night when the soldiers burn the shit from the outhouses distributed along the periphery of the base.

The 400 men of the Battalion are commanded by Lt. Colonel Mark Huron, a handsome, avuncular man who knows most of his soldiers by name and makes a point of accompanying them on raids in the middle of the night. A huge part of the war on the guerrilla fighters is responding to tips about who's responsible for their training and funding.

Huron tells me these tips are carefully weighed in light of the informant's past reliability, but are considered especially useful when two informants finger the same man. If no evidence is found the man will likely be let go, but if multiple weapons or bomb-making materials are found he's taken in for questioning by the Americans.

Huron wryly tells me about a translator at the base who kept mysteriously disappearing whenever a bomb went off somewhere. Suspicious, a squad raided his house and found electric wire and switches, and arrested the man. He was later let go when it was discovered that he was an electrician who had to respond to emergency calls in neighborhoods damaged by bomb blasts.

It's 1:00 am and I'm waiting in a humvee beside a small canal, the black water reflecting the bright stars of Orion overhead. Tikrit is a small, rural town, criss-crossed with irrigation canals and dusty pastures. I'm with Capt. Ken Reed, one of Huron's most trusted officers, a tall, laconic black guy who's intensely focused on his mission.

Reed is guiding his men by radio on a raid of three houses simultaneously, to detain a sheik and several tribal elders implicated in IED attacks. I can just make out Huron's vehicle across the canal, where he's sitting with his XO, Maj. Ron Zimmerman.

Somewhere in front of us forward elements from Bravo and Charlie companies are poised, peering at their targets through night-vision lenses. Reed gives the order to go in and there are several minutes of silence. The response comes that the area is secured and we drive up.

Twelve men are being led out, their hands cuffed, and they're made to sit down in a circle. They're mostly older men, in their 40s, dressed in traditional desh-daashes that the soldiers rather insensitively refer to as "man-dresses."

All say they are farmers, the usual response given by suspects. Of the 12, eight men are released, with apologies, while four are taken in, including the sheik and his son, both of whom proudly state that they were in Saddam's special forces. Weapons, wiring and switches are also discovered.

Later a fifth man is picked up, a man named Naif, who formerly was a translator for the base. His wife is wailing disconsolately, and as we leave, the family breaks into a rather practiced group wail. Huron shakes his head. "That used to really bother the soldiers -- they felt like the bad guys. But it became clear that many of these people are trying to kill us. The ones we can't get real evidence against get released."

The rise of IED attacks has clearly been effective and 4th ID is spending a lot of time combating them. When one goes off, a quick reaction force is dispatched to search the area. Suspects are often found, and if their houses contain bomb-making equipment they're bulldozed.

Maj. Troy Smith of Task Force Iron Horse insists that they're making progress in Tikrit. He says only two to five percent of the population is actively resisting the occupation, but this of course can only be a guess. A reporter I talk to from the San Francisco Chronicle says, based on her experience in Ramadi, that if the Americans think the resistance is only a few fedayeen, they're kidding themselves.

"There are no fedayeen there," she states bluntly. "The people of Ramadi hate the Americans. If I was in their shoes I don't think I'd personally pick up an RPG, but I can certainly understand those that do." It's impossible to tell how accurate her assessment is, because she's so clearly against the occupation. I tell her that in Baghdad I've spoken to many Iraqis who support the Americans. We don't find much common ground.

Samarra
When the soldiers in Samarra refer to the "war" they're not talking about the one that ended last May. They're talking about their day-to-day experience.

Samarra is an attractive rural town southeast of Tikrit, on the way to Baghdad. It's claim to fame is its stunning ancient minaret with an exterior spiral walkway to the top, as well as its central mosque which is graced with a brilliant gold dome. Both structures can be seen from anywhere in the town, so it's easy to orient yourself. Samarra is 95 percent Sunni, and an active center for resistance against the Americans.

I spent a week with the soldiers, MPs and Counter Intelligence officers of CMOC, a small base in the thick of the town, which on a good day only gets one attack by mortar or RPG. Staying at CMOC (Civil-Military Operations Center) feels a little like being with the Robinson family of Lost in Space. The small walled compound is no more than a lightly protective shell, its two platoons of men and women gossiping about each other as much as worrying about the daily possibility of injury or death.

CMOC isn't the type of clean, well-ordered American base I'm used to -- it's dingy and strewn with debris, the walls have holes from RPG hits and one of the three shitters has been blown up by a lucky mortar round. Capt. Shermer was in it when the first round hit. He yanked up his trousers and ran, seconds before his toilet was blown to smithereens. At CMOC, soldiers sit at the front of the old building, gazing past the mortars and the gate at the outside, like sailors contemplating a tempestuous sea.

The women here are part of the MP platoon known as Wolfpack 1 from the 64th MP Co., based in Ft. Hood, Texas. In the humvee that gives me a ride from Tikrit to Samarra I'm surprised to notice that the gunner is a woman; so is the MP in the seat in front of me. Indeed, Wolfpack's highest ranking officer at the base is 1st Lt. Boudreaux, a petite and strikingly pretty black woman who wields a lot of authority when she needs to.

The 4th ID element is a mortar platoon commanded by Capt. Kosuda, whose startlingly youthful features and optimistic nature constantly remind me of the Belgian comic book character Tintin.

The night I get there the mortar-men are firing illumination rounds over the city, "just to let them know we're still here." At 50 yards away the crackling blasts are still deafening. A couple of hours later there's moaning by the front gate. An older Iraqi woman enters with her son, both shaking with grief. Her other son, who sells CDs and lighters to the GIs, has just been killed in an RPG attack on his house.

"You can sent someone, please mister, what can you do? What can you do -- My brother, he is, he is. . . They have dead him!" The young man gestures wildly. His frustration at the language barrier at last overcome by his grief, he sobs, and punches out at the air, himself.

Boudreaux has a problem -- the shooters will have long disappeared into the night. She sends some of the Iraqi cops who use CMOC as a provisional base to investigate. The first volunteer is a young go-getter who the Americans have dubbed Super-Cop for his policing abilities.

About an hour later there's shouting at the gate. Super Cop has returned with a suspect, a young man that he's beating and threatening to shoot as he drags him in the gate. Super Cop says that as they were returning to the base they spotted three men on bicycles carrying an RPG. They gave chase but caught only this one, no weapon.

Emotion is running very high, and as Super Cop continues beating the suspect some of the soldiers cheer him on. Others pull him off. The suspect is crumpled in the corner, and now Mike, a Lebanese-American translator and former Falangist fighter, stands over him muttering insults.

"Fuck you," replies the prisoner. In a rage Mike kicks him. To my amazement one soldier is standing up for the prisoner, talking calmly to the others.

"Hey, wait a second. We don't know the whole story. . . we weren't with Super Cop. . . there's no RPG, so they'll probably release him in Tikrit. If he's not an enemy now he'll definitely be one later."

The tension subsides and the prisoner is booked and jailed with other suspects awaiting transport to a larger base.

A couple of days later Capt. Kosuda invites me to join him on a trip to Stoddard Base to sit in on the daily battle plan meeting. It's presided over by a Major Casey, a hulking man who likes his meetings short and to the point. Viewing slides of maps, all the representative officers of Samarra go over the last 24 hours' worth of attacks and small engagements and present plans for the next day. Without breaking a beat the next slide shows sports scores while someone reads: "Tiger Woods won his 5th straight championship. . . . Last night Florida and the Cubs. . . ." No one cracks a smile, and the meeting adjourns.

I'm invited to join a foot patrol with a platoon from Stoddard that night. The Captain asks me to please obey the soldiers' orders. "They will risk their lives to get you out if you get shot."

After dinner I link up with a couple of officers and we climb into a Bradley. A third man jumps in. He says his name (which I can't remember). "I'm from Queens, I've killed a few people and I like what I do." It's narrow, dark and airless inside, only two tiny battle-hardened glass slits to peer through. The noise of the engines is deafening. Soon we're in a convoy of Bradleys and Abrams tanks roaring towards the dismount point in the last light of the day.

For an hour we patrol the neighborhood, some 20 men moving quickly and quietly from street to street, among the many Iraqis who are outside enjoying the night air. They watch us warily. Kids on bikes grin. It's weird, like playing an elaborate battle game in a middle-class neighborhood.

But just as we settle back in the Bradley we hear the deep machine chatter of the Mark 19. I can see red tracer rounds flying through the small window. From the radio we learn that an RPG was fired at the rear Bradley. The gunners are conducting recon by fire, trying to lure the shooter out, but he's gone.

I get dropped off at the front of CMOC, but there are no guards as I approach the front gate. Where the hell am I? The Bradleys are taking off, and I bang on the gate, shouting. A figure emerges on the roof of the building inside the compound. "Go to your left!" I realize that I'm at the entrance to the Special Forces compound next door to CMOC, and dash to the next building. I can hear clapping from the SF building as I locate the right gate.

That night there's a mortar attack: a distant boom, followed by a louder boom, and everyone jumps for the building entrance. Luckily for us the next explosions recede, heading off towards Daniels base.

The Iraqis can always be counted on to aim badly. There's no time for adjusting mortar fire -- the Americans can plot the trajectory of incoming rounds and fire back within half a minute, so the Iraqis just estimate a first shot and then fire off as many rounds as they dare. Usually the soldiers can't get authorization to return fire because the location is deemed too close to a civilian neighborhood.

RPG shooters tend to be poor people who get paid to squeeze the trigger. Using an RPG effectively takes some training, so more often than not the grenade goes wild. Still, there's a hole in the wall just across from where I'm sleeping from an armor-piercing RPG that turned out to be a dud.

The week I'm at CMOC is considered uneventful after a two-month spree of firefights, attacks and IEDs, which subsided after a huge weapons bust in the industrial sector of Samarra. Five flatbed truckloads of weapons and ammunition were carted away.

Everyone here expects things to get rough again when the enemy resupplies. In the meantime the counter intelligence officers are busily hurrying along the formation of a local government with the cooperation of the sheiks of Samarra. Like everywhere in the Sunni triangle it's a breathless race to win over the people who'll ultimately decide Iraq's future, the Iraqis themselves.