Updated

A key turning point in the U.S.-led war against the Iraqi insurgency came even before last winter's troop surge, FOX News has learned.

A map drawn by Al Qaeda in Iraq leader Abu Musab al-Zarqawi — who was killed last year by U.S. forces — turned up last December in an Al Qaeda safe house and essentially gave U.S. war planners insight into the terrorist group's methods for moving explosives, fighters and money into Baghdad.

Click here to see the map, which was obtained by FOX News (.pdf).

"The map essentially laid out how Al Qaeda controlled Baghdad. And they did it through four belts that surrounded the city, and these belts controlled access to the city for reinforcements and weapons and money," said Maj. Gen. Bob Scales, a FOX News contributor who recently visited Iraq.

"And [U.S.-led forces] simply made the decision to reduce these belts one at a time, and essentially what that did was it choked off Al Qaeda's access to the city. And once that was done, Al Qaeda had no alternative but to leave the city, to leave the belts and to retreat into the city of Baquba," Scales said.

The map showed four rings around Baghdad, nearly identical to rings former Iraqi dictator Saddam Hussein once created to protect the city.

U.S. military planners used those maps to choke off Al Qaeda, moving ring by ring, hunting and destroying Al Qaeda in Baghdad, flushing them out of their urban strongholds and picking them off as easy targets in the desert.

The troop surge was announced Jan. 10 and began soon after that. Gens. David Petraeus and Raymond Odierno took a risky but calculated move to send U.S. troops out of main base camps and set up small patrol stations that were jointly manned with Iraqi forces, essentially living among Iraqis in Baghdad. It made it easier for intelligence to surface but made U.S. troops easier targets.

U.S. forces seized on an opportunity as Al Qaeda gathered in the northern city of Baquba. The surge allowed troops to encircle Baghdad, and the insurgents fled into the desert, making them even more vulnerable to U.S. forces.

"What this offensive did is it essentially cut the head off the snake," Scales said.

The explanation for the turning point came as new reports of a more peaceful Baghdad surfaced.

The New York Times reported Tuesday that Iraqi civilians were returning to more normal rhythms of life, which had been disrupted first by Hussein's oppressive rule and then by fighting that ensued after the 2003 U.S. invasion.

Click here to read the full report in The New York Times.

The Times reported that days now pass without a car bombing, unheard of in the height of the insurgency. The number of bodies appearing on the streets has fallen from a peak of 35 eight months ago to five a day, and homicide bombings dropped to 16 in October, half as many as last summer and down from a peak of 59 last March.

The Times report, based on interviews with 50 Baghdad residents, said that people are moving freely about Baghdad for the first time in nearly two years. While there still are places people do not enter, there is more travel between Shiite and Sunni areas for everyday routines such as work, shopping and school. Significantly, this travel occurs even after dark, the Times reported.

Other signs of emerging life included women displaying wedding bands, liquor stores opening up and children being able to walk between libraries and their homes.

FOX News' Jennifer Griffin contributed to this report.