BAGHDAD — Gen. David Petraeus hops out of his helicopter in the heavily Shiite district of Rusafa, to check out one piece of the U.S. strategy to stabilize Baghdad.

Petraeus strolls briskly through a 110-degree haze toward the Bab al-Mouadem police station. A unit of the Second Infantry Brigade Combat Team from Fort Carson, Colo., is based here in primitive conditions. The new strategy partners U.S. troops with Iraqi forces in the heart of troubled Baghdad neighborhoods. The hope is that protection for locals will lead to tips about hard-core insurgents.

It's easy to be skeptical. Overall, violence in Iraq is still rising, according to a recent Pentagon report. (Sectarian killings sharply decreased when the surge began but are going up again.) After months of a U.S. troop buildup, only 40 percent of Baghdad is secure, according to Gen. Raymond Odierno, the second-ranking U.S. officer in Iraq.

Yet signs exist that the strategy could gain traction. The military's goals are bluntly realistic, unlike the rhetoric in Washington. Being on the ground in Baghdad focuses the mind.

In contrast to U.S. politicians, no one here talks of "victory." Military strategists know there are far too few U.S. boots on the ground. They also know that the ultimate outcome depends on Iraqi leaders and whether they can — or even want to — hold the country together. With that in mind, the short-term U.S. goal is basic.

"We are trying to stem the cycle of violence," says a senior counterinsurgency adviser to Gen. Petraeus.

Here's how the cycle works: Al-Qaida infiltrates Sunni neighborhoods and intimidates locals, then sends car bombs to attack neighboring Shiite districts. This leads to a backlash by Shia death squads, which angers Sunnis and bolsters al-Qaida's appeal. "It's like an engine out of control," the adviser says.

"A lot of operations will be aimed at al-Qaida over the summer," Petraeus told me. "We can get into al-Qaida sanctuaries as we never did before."

One operation began Tuesday in the province of Diyala, east of Baghdad.

By September, when Petraeus and U.S. Ambassador to Iraq Ryan Crocker will report to Congress, they expect to have some idea of the impact on al-Qaida. The surge will probably last until March; in theory, it could create some breathing space for political reconciliation.

"It will take longer than September," Petraeus said, "for this to have a fair chance."

The best cause for hope is that major Sunni tribes have turned against al-Qaida in Anbar province and in the belt around Baghdad. The group's viciousness alienated sheikhs who once tolerated its presence. Tribal fighters will be crucial to stabilize troubled areas; U.S.-trained Iraqi forces are often unreliable.

Many Iraqis are skeptical; four years of shifting U.S. policies have left their country a shambles. Shiite and Kurdish officials argue the real threat to Iraq's future is not al-Qaida, but Saddamists who use equally vicious tactics to pursue a Baathist restoration. These officials fear naive Americans may arm Sunni militias that claim to have turned against al-Qaida but will use the weapons against the Iraqi government.

Indeed, Americans may arm some of the wrong forces. U.S. commanders grasp that, but feel they must take the risk. If al-Qaida is checked, they believe, Saddamists will also be weakened, leaving a less-violent insurgency that can be contained.

It is a strategy based on grim realism. The widespread assumption among senior U.S. military commanders is that a U.S. military drawdown will begin by early 2008 — both because American politics will demand it and because the military is overstretched.

No one contemplates a full pullout, however, and no decision has been made on how many American troops will remain. The numbers will depend on how much the security situation improves.

"The fundamental question," said the senior adviser, "is whether there will be a withdrawal in a broadly stable security environment, or a deteriorating situation that will keep going down."

If al-Qaida can be checked, he said, the United States might "get out without a major civil war that spills over into the region and without leaving an al-Qaida safe haven." Iraqis would have an opportunity to make political progress — if they care to seize it.

In other words, this strategy aims to make it possible to draw down U.S. troops without precipitating a worse Iraqi disaster. Unlike past U.S. strategic fantasies, this one at least sounds real.