As about 40 Marines walk toward a mud and stone house in a front-line village here, a bearded man in a long white robe emerges, his arms raised to show he is unarmed. He seems relaxed. Behind him, a woman in a black shawl holds a young girl close to her dress. The Marines maneuver toward positions on either side of the house, their rifles trained on surrounding fields.

Maj. Frank Simone, a Marine reservist, turns to an Iraqi who serves as his interpreter. "Ask him if he minds if we search the house."

The man in the robe begins a long answer in Arabic, and the interpreter starts to translate: "He says that the area is outside of Iraqi government control and there is nothing to worry about here."

But Simone, who has the street smarts of a drug enforcement agent, which is what he is in his home town of Hermosa, Calif., cuts him off. "Tell him we need to search the house," he says. "Especially because of those two white pickup trucks out front." White pickup trucks have been used by Iraqi fighters in the area.

Plagued by nightly ambushes as they make their way north through Iraq, the Marines are conducting regular foot patrols in villages such as this one, located just off a major road. The war they find here is not the one they came to fight. There are no enemy tanks or infantry formations, just houses -- most of them with no electricity or running water -- and people in civilian clothes, some looking on with open hostility, others with friendliness that may be feigned.

It is a Vietnam-style environment with high tensions on both sides -- and, often, ambiguous results. U.S. troops walk through with weapons poised, unable to understand words spoken to them, detaining people they think might be shooting at them the next night, but often unsure if they get the right ones.

"We are here to show a presence, to let people know we're here, and to make sure everything here is safe," said Lt. Seneca Todd, who today led the platoon from the 1st Battalion, 7th Marine Regiment's Bravo Company on their first patrol since arriving in Iraq. "We're not trying to frighten anyone who isn't doing anything wrong, but even a harmless-looking home can be a hornet's nest."

To begin the search of the farmer's house, a dozen Marines leave their positions and approach the two main doorways. As they are about to enter, the black-bearded man, who looks to be in his late thirties, explains to the interpreter that he has a weapon inside, an AK-47 assault rifle. He says that he has it to defend his family and livestock, including some chickens and ducks that are wandering around in the yard.

"How many weapons are inside?" Simone asks.

"One."

"And how many other people?"

"One more woman, and two other children."

"Hold up!" Simone screams to the Marines, who are inches from the door, poised to enter as soon as the order is given. And then, to the Iraqi man: "Clear out all of the women and children before we go in."

A second woman emerges from the building with a child on either side. She is crying. Through the interpreter, Simone tells her not to worry, that everything will be fine.

The Marines enter the home, in two-man teams. Soon one emerges with the AK-47 that the Iraqi man had mentioned, and leans it against a wall. "You'll get this back when we go," Simone tells the man. It's common for ordinary Iraqis to have such a rifle. "Have you seen Iraqi troops near here? How recently?"

He is told that there were soldiers in the area five or six days ago, but that they are now gone.

And then, from inside the house, an excited Marine shouts: "Hey, we have a machine gun in here!"

The farmer turns nervous, and begins speaking quickly. He tells the interpreter that his children are ill from drinking the water, and that they have no place to go to school. "Tell him that once Saddam goes down, we're gonna bring food, medical supplies and water."

Platoon Sgt. Eric Strause walks out carrying a light RPK machine gun, which the Marines found wrapped in blankets in a bedroom.

"He's not keeping it," says Strause, 32, of San Antonio. "He never told us he had it."

"Ask him where he got the machine gun," Simone says. The man says that he bought it.

"Tell him that it's too dangerous to U.S. troops," Simone says. "We are taking it."

A moment later Todd, 23, from Monroe, N.Y., brings up a shiny black sighting device used for aiming mortars. It was found in the dresser next to the man's bed. Earlier in the day, Marines from a different platoon had found a mortar tube in a nearby field.

"Ask him where he got this," says Simone, his jaw now clenched. The Iraqi man waves his arms as he answers. He says he has had the sight since 1991, and that he uses it for hunting.

The Marines continue searching through the rooms. Damage is being done now. One Marine tears open bags holding grain and sifts the contents. Another pops the lids from cans of vegetable shortening.

The women, one of whom is now crying inconsolably, gather their children in a corner of the courtyard. In another corner, a black and white dog that has been circling the Marines begins to bark.

Simone says he's seen enough. "Tell him he's got important information and we're going to take him to talk to some of our people," he directs the interpreter. "He can tell his family he'll be back in a couple of hours."

Inside the house, the search continues. A Marine finds a pistol in the living room, underneath a couch. Another uncovers a flare gun, several rusted AK-47 ammunition clips, and a duffel bag full of cash.

And then, from inside the house: "Sir, we have an RPG in here," referring to a rocket-propelled grenade. A Marine emerges with an old-fashioned-looking wooden tube, with a metal apparatus fixed underneath it. "Cheap, but effective," he says. "These things tear our vehicles apart."

Strause has just ordered a group of Marines to go across the street to search a trailer parked in the yard. But now he turns quickly and returns to the house. "We're gonna do a much better search here," he yells to the Marines outside the dwelling. "We're gonna tear this place apart."

Simone leads the bearded man away to a waiting Humvee. The Marines return to their vehicles, handing out yellow, plastic-wrapped humanitarian rations to the children. "We want them to know we're friendly," says Simone.

The Marines prepare to move to the next set of houses.

In the end, they aren't sure whether they've found a fighter or merely upended the house and frightened the family of a man who intended no harm to them. They found a lot of weapons, but it's conceivable that the Iraqi army stopped by days earlier and distributed guns that people couldn't refuse. All the Marines are sure of is that there's another house to check, and another one after that.

Troops with the 2nd Battalion, 8th Marine Regiment search near Nasiriyah for Iraqi militia fighters who have carried out guerrilla-style attacks.An Iraqi talks with a Marine from the 7th Regiment during a search of his home in the central part of the country.