ASHEQUE, Afghanistan - Zhari district in Kandahar province, the cradle of the Taliban movement and once again a stronghold of the insurgency, looks set to become a battle zone soon as 2,400 U.S. troops prepare to try to reclaim the region for the Afghan government.

Zhari is the last major piece in the slow-moving, behind-schedule military operation to oust the insurgents from Kandahar province and safeguard the city of Kandahar, the second-largest city in Afghanistan, to the east.

Mullah Mohammed Omar founded the extremist Islamic Taliban movement in Zhari - which was created recently from parts of two other districts - and in 1994 led a popular uprising against feuding warlords who were setting up roadblocks, robbing travelers at gunpoint, and molesting their children.

The Taliban first secured the area, where Omar ran a seminary in the village of Singesar, and the part of National Highway 1 - a national arterial road - that passes through the area, then went on to conquer much of the rest of the country.

Taliban fighters abandoned Zhari in the face of the U.S.-led invasion in 2001 but made a return in 2006. They have established an administrative structure, including tax collection and courts.

"This area is the Taliban's Washington, D.C.," said Lt. Col. Johnny Davis, commander of one of the three fighting battalions of the 101st Airborne Division that were deployed to Zhari in May.

He noted that until this summer, the U.S.-led international force had not made Kandahar a priority, devoting its resources instead to adjacent Helmand province.

"The required concentration of coalition forces has not been here, but the concentration of Taliban is just as high as Helmand," said Davis, 42, commander of the First Battalion, 502d Infantry Regiment.

For much of the time since 2006, about 200 Canadian soldiers had fought a losing battle to clear the Taliban out of Zhari. Today, the 101st Airborne's battalions provide a combat strength of 2,400 soldiers there, and securing Highway 1 through Zhari is now their task.

The insurgents are holed up in a 25-mile sliver of lush farmland south of the highway that's known to the U.S. military as the "green zone," where trees, irrigation canals, and fields of grapes and pomegranates provide excellent cover.

The terrain is ideal for guerrilla warfare.

"These grape fields are agrarian trench lines. This is not Napa Valley," said Capt. Dan Luckett, 26, the executive officer at combat outpost Asheque, which is inside the Zhari farm belt, surrounded by Taliban-held villages.

"You can secure the highway all day long, but what's affecting it is the green zone, the staging points," said Luckett, from Norcross, Ga., who has one prosthetic leg, the result of a homemade-bomb strike in Iraq.

Zhari is sparsely populated. The town of Senjaray, in the east of the district, is the only major urban center, and the Taliban makes its presence known there almost nightly with attacks on coalition or Afghan security forces.

American forces believe there are signs that the Taliban doesn't have popular support, at least in parts of Zhari. Many villagers have abandoned their homes because of the Taliban presence. The poorer ones moved just north of Highway 1 to makeshift new communities, while the wealthier ones moved to Kandahar city.

"I was surprised that people were afraid of the Taliban here," said Capt. Brant Auge, commander of the Asheque outpost. "I had expected a lot of hard-core support. So we have a chance."

This year, the U.S.-led International Security Assistance Force's major offensives have been an operation that began in February to wrest control of Marjah, a town in Helmand province, from the Taliban amid a blaze of publicity but mixed results, followed by the lower-key attempt to secure parts of Kandahar province.

Coalition forces already have secured much of the area north of Kandahar city - the Arghandab Valley, which provided the other major route into town - and moved to improve security within the city.

Zhari is the last piece of the Kandahar puzzle.