BAGHDAD — It was just after lunch Thursday when the "surge" arrived at Haidar Karam's doorstep.
Out of nowhere, about 50 U.S. troops appeared and circled his northeast Baghdad neighborhood. Half a dozen Humvees arrived 15 minutes later. Snipers took up positions on rooftops. Troops stopped vehicles from moving.
They were the leading edge of a Baghdad security plan called Operation Law and Order, part of what the Bush administration has dubbed a "surge" in U.S. troops in Iraq.
After weeks of delay, the promised crackdown and troop increase were boldly evident Thursday during an hours-long tour of neighborhoods throughout the war-weary capital of 6 million people, where sectarian fighting kills an average of 100 residents a day.
A U.S. officer approached Karam, handing the government clerk a piece of paper with a phone number and an e-mail address to contact authorities if there was any trouble in his Shiite-dominated Shaab neighborhood.
He told Karam through an interpreter that American and Iraqi forces were going to secure the neighborhood. They were going to install a one-megawatt power generator.
"I told him, 'I find that difficult to believe,' " Karam said. "Our government always lies to us."
At that, the U.S. officer laughed, Karam said.
"We will prove it to you!" he said the American told him.
U.S. and Iraqi forces conducted raids, searched abandoned buildings and patrolled neighborhoods as part of the security plan, which officially began Tuesday evening.
At least 3,000 additional U.S. troops and about 2,000 Iraqi counterparts have arrived so far.
Despite the crackdown, authorities discovered the bodies of at least 20 men shot dead and dumped in west Baghdad. Dozens were killed or found slain around the country.
Troops to stick around
Under the security plan, units of U.S. and Iraqi forces will attempt to clear neighborhoods of unauthorized weapons and insurgents. They will stay rather than returning to base, in an attempt to halt spiraling sectarian warfare between Shiite Muslim and Sunni Arab gunmen, lure residents back to their homes and rebuild the economy.
"We are establishing a stronger presence throughout the city," said U.S. Army Maj. Steven F. Lamb, a spokesman for American forces in Baghdad. "We're going to have a 24-hour presence, which is going to stem the sectarian violence. All available troops that we can have on the street are on the streets."
On Thursday, U.S. forces often found themselves back at the small bases they used in the early months after the 2003 invasion. The facilities were abandoned as U.S. commanders under the direction of Army Gen. George W. Casey Jr. decided to lower the American profile in neighborhoods and hand security over to Iraqi forces.
Since then, a once-vibrant Baghdad has become a forbidding maze of concrete walls and concertina wire roamed by mysterious gunmen, where petrified residents rush to their homes before dark.
The Dora district in south Baghdad was among the first neighborhoods targeted by the security plan. With Humvees and armored vehicles protected by aircraft, U.S. troops swept in Wednesday, setting off stun grenades before storming houses in search of insurgents.
By Thursday morning, explosions were shaking the district and security forces at newly established checkpoints had begun searching cars.
"Just four days ago, gunmen never stopped attacking checkpoints and firing at the Iraqi army," said journalist Ghesan Jabouri, a Dora resident. "Now that's all over."
Still, two car bombs killed at least four Iraqis and injured 20 in Dora, and by midafternoon the district's bullet-scarred main streets testified to the enormous challenges facing U.S. and Iraqi forces. Many of the closed shops were painted with an encircled X, a warning by insurgents not to reopen. Jittery Iraqi soldiers at a checkpoint stood guard, waving past the smattering of drivers braving the streets.
In nearby Sadiya, a violent Sunni neighborhood, U.S. troops stood near the kitchen of a home and watched Iraqi counterparts search the modest single-story house for weapons.
"What, grandma?" an Iraqi soldier joked to the family's matriarch, a woman in her 70s. "Don't you have any rocket-propelled grenades or roadside bombs?"
"No, son," she replied, laughing. "What would we do with such cursed things?"
The soldiers seized a handgun but let her family keep an AK-47.
Numerous checkpoints staffed by Iraqi soldiers and police directed the sparse traffic.
"We are very motivated," said a burly young Iraqi army lieutenant standing guard on the outskirts of the Yarmouk district downtown. "This security plan is a significant turn of events."
Streams of unmarked white SUVs filled with masked security officers pointing assault rifles at motorists passed by. Blue-and-white police pickups with makeshift plates of armor slapped to the sides kicked up dust and exhaust as they sped past motorists.