Last month, 1,000 U.S. Marines swept through the Iraqi insurgency stronghold of Karabila in a three-pronged, three-day offensive they had dubbed Operation Iron Fist, meticulously searching every house on their way and leaving behind a town completely devoid of enemy fighters.
But by last week, guerrillas linked to al Qaeda were running Karabila again. Marines conducting another offensive -- this one called Operation Steel Curtain -- were once more fighting their way through Karabila's dusty streets as insurgents greeted them with small-arms fire, roadside bombs and houses rigged with explosives.
The fall and subsequent regrouping of insurgents in this town on the border with Syria were reminders that in Iraq, where front lines are nowhere and everywhere, the concept of territorial control remains ephemeral.
"There's definitely an issue of when (the U.S.-led coalition troops) leave, who controls the land," said Michael O'Hanlon, who heads the Iraq Index project at the Brookings Institution in Washington.
Deficient intelligence on swaths of Iraq where the military presence is limited and the shifting nature of the insurgency make areas of control difficult to pin down, analysts say.
On the surface, Iraq can be split into three major areas of influence:
-- Shiite militias and Iraqi government forces control most of the south and east;
-- Sunni tribes, many of them linked to insurgency groups, run north-central and north-western Iraq, where guerrillas mount daily attacks on U.S. forces;
-- Kurdish forces made up of peshmerga fighters who once fought against Saddam Hussein and now ostensibly are loyal to Baghdad control the mountainous north.
Coalition forces control their military bases, the streets they patrol when they patrol them and, depending on the success of the troops' individual counterinsurgency operations, the areas surrounding them.
But in reality, the map of Iraq portrays a geography charting ethnic and tribal rivalries dividing into far smaller and more intertwined areas of influence. In Baghdad alone, several Sunni Arab insurgency groups, Shiite militias with different loyalties, U.S. troops and Iraqi government forces compete for control over the capital.
"Whoever thinks Iraq is split" into large monolithic areas of control, "I say, they need to get a bigger map," said John Pike, director of GlobalSecurity.org, a security think-tank in Washington.
Rita Katz, director of the U.S.-based SITE Institute, which monitors Islamist Web sites and news operations, said that outside the fortified perimeters of coalition military bases and Baghdad's heavily guarded Green Zone enclave, where the Iraqi government and the U.S. Embassy are based, "the country is really controlled by different and many insurgencies and militias. There are more and more insurgency groups that have come to light in the last few months. ... They control different places.
"The (Iraqi) National Guard doesn't control everything; neither does (the) police," Katz said. "And the Americans and the allied forces are everywhere, but they are nowhere."
O'Hanlon argued that coalition forces and Iraqi government control most of the country, and that insurgency groups cannot claim to control anything.
"The insurgents are only able to deny control to others," he said. "There are ... three potential groups in charge of Iraq today: one is the U.S. and Iraqi official forces, the second is the militias, and the third is anarchy."
Anarchy, O'Hanlon said, dominates "probably a third of Baghdad and Anbar province and, depending on the day, parts of (the northern city of) Mosul -- overall probably about 15 percent of the country, but, unfortunately, a very important 15 percent."
In the south, "Basra and that region is mostly the area of militia control. Same with Kurdistan. Twenty-five percent of the country are militia-dominated," he said. "Sixty percent are officially controlled almost all the time by the coalition forces and the Iraqi government, but even where it's government controlled there can still be a lot of violence. There are places where the government more or less controls, sort of can push a convoy through, but doesn't control block by block."
One reason analysts find it hard to agree in their assessments of who controls what in Iraq is that it is very difficult to get reliable information in the war-torn country.
As it has since the insurgency began, the military suffers from lack of reliable intelligence. U.S. commanders, most of whom do not understand Arabic, often have to rely on Iraqi informants and aerial shots of the terrain to distinguish friend from foe. They must ask their interpreters each time they want to know whether new graffiti on the wall of a hostile town is a mark of a new insurgent network, a threat to American and Iraqi government forces or simply an advertisement for a new tea shop.
"The general lack of American cultural preparation for this campaign -- that is, not enough people with language skills to understand even the basic information -- lies in the basis of failure to combat this insurgency," said John Arquilla, co-director of the Center on Terrorism and Irregular Warfare at the Naval Postgraduate School in Monterey.
"Our military operations are almost perfectly designed to deprive us of the intelligence we need," Arquilla said. "We tend to locate something and then destroy it. When you fight a network, the more you take out, the less you know."
U.S. military commanders on the ground rarely admit publicly that enemy fighters control any territory. U.S. Marine Lt. Col. Julian Alford, commander of the 3rd Battalion, 6th Marine Regiment stationed in western Iraq, broke new ground in September when he acknowledged in an interview with The Chronicle that insurgents had controlled Karabila and four neighboring towns on the border with Syria since summer. His brigade commander, Col. Stephen W. Davis, had denied it a day earlier.
And if trying to understand Iraq's difficult ethnic and religious terrain were not hard enough, control over individual sections of towns or desert may vary day by day, as exemplified by the successive fights for Karabila.
"In a conventional war, you control the rear and the front is a boundary between what you control and what you don't control. But such distinctions are irrelevant in counterinsurgency," said Pike.