NEAR ISKANDARIYAH, Iraq - Brig. Gen. Edward Sinclair, touring what amounts to a small city he is building on a former military airfield here, hopped out of his Humvee and marched over to a truck parked near a battery of howitzer guns pointed skyward.

"It's General Sinclair," he announced. "Get your butt out here so I can talk to you."

As soon as Lt. Marshall Clay poked his head out, Sinclair asked, "Who told you to set up here?"

The battalion, said Clay, tentatively.

Sinclair shook his head no. Clay had set up operations on what was going to be the parking place for a general's helicopter.

"All this has to go," he said, gesturing to Clay to move his howitzers away from the end of the runway. "You've got to go down there."

"Roger, sir," Clay said. "Roger, sir."

Sinclair patted the young lieutenant on the back. Then he set off again, architect, construction boss and city planner for this emerging forward base for the 101st Airborne Division.

This former Iraqi military airfield just south of Baghdad is turning into a huge staging ground for forays to the capital, with up to 17,000 troops expected by week's end. As assistant division commander, the general must make sure everything goes where it belongs within about 6 square miles of sand.

Now it's a runway with scattered, and very flimsy, metal buildings with corrugated roofs. It needs to become a well-organized settlement with tents for troops, refueling depots for trucks and generators and repair shops for weapons and broken-down Humvees.

Huge numbers of trucks and people are heading this way, and Sinclair has to find a good place for each of them.

The people and equipment are necessary to keep the war effort going, but many of those here now are jealous of those on the frontlines, wishing they too were part of the dwindling fight in the capital.

Some soldiers, at least, have gotten to go on missions just outside camp.

They have found vast storehouses of ammunition and weapons nearby, as well as some fighters who apparently never got word that the regime of Saddam Hussein has fallen.

Yesterday, soldiers in the 3rd Battalion, 327th Infantry Regiment detained 12 prisoners. Of the four held by scouts, one had Iraqi military identification and one a Baath Party ID. The scouts found a detailed map showing where rocket-propelled grenades and other arms were stored.

Before the war the airfield, like the sprawling military complexes that surround it, was under the control of the Iraqi regime. By the time Sinclair arrived Monday, it was the domain of civilian looters and wild dogs.

Since then, its transformation into a U.S. base has moved apace. The airfield seems equal parts port, construction site and war zone. The roads are clogged by Humvees, tractor-trailers, large tanks and small all-terrain vehicles called gators.

One hears everywhere the hammering together of tents, the thwap-thwap of helicopters, the rumble of bulldozers, the strain of tank engines and the groan of giant cranes hoisting metal containers.

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