An insurgency that kicked off with frenzied pot shots and stray bombings by seemingly ragtag gunmen has coalesced into an effective, guerrilla-style war of attrition featuring a daily drumbeat of attacks interspersed with sensational strikes.
The insurgents have learned to mount targeted bombings, crippling sabotage, helicopter shoot-downs and — in this volatile city north of Baghdad — a synchronized urban ambush with scores of fighters firing machine guns, rocket-propelled grenades and mortar shells at U.S. formations.
"There was coordination — to say otherwise would make no sense," said Col. Frederick Rudesheim, commander of the 3rd Combat Brigade here, which said its forces killed as many as 54 insurgents in the Nov. 30 firefight, a figure widely disputed by residents. "They put together an attack. And they didn't do it overnight."
In an effort to assess where the U.S.-led occupation stands at the end of the year, two reporters spent several weeks interviewing commanders, regular soldiers and pro- and anti-American Iraqis throughout the battle zone. Although U.S. officials remained confident of victory, they and almost everyone else agreed that an already bloody conflict is about to get worse.
No one anticipates anything but fiercer combat until at least next summer, when the U.S.-led coalition is scheduled to hand over control of Iraq to an interim government and troop levels are expected to decrease to about 100,000 from the current 112,000.
"We expect to see an increase in violence as we move forward towards sovereignty," Army Lt. Gen. Ricardo Sanchez, the top U.S. commander in Iraq, said in a frank assessment echoed by L. Paul Bremer III, the civilian administrator.
But U.S. officials point to progress: a drop in daily attacks against coalition forces by more than 50% — from a high of 55 daily attacks a month ago to 20 today — as the Army launched several major offensives involving bombing runs, house-to-house searches, enhanced patrols and the encirclement of entire villages with barbed wire.
The Army says improved intelligence gathering, boosted by financial rewards for informers with accurate information about attackers, has resulted in the breakup of several insurgent cells, including the ones believed responsible for the October attack on the Al Rashid Hotel and the roadside assassination last month of seven Spanish intelligence agents.
Yet commanders acknowledge that busted cells have demonstrated an ability to regenerate, replenished by the legions of former Iraqi army officers, disenfranchised Saddam Hussein loyalists and angry young men without jobs reared on anti-Western invective who can earn some cash by attacking soldiers and allies. As strikes against heavily guarded coalition forces have decreased, assaults on "soft" targets — foreign contractors as well as police officers, public officials and other Iraqis seen as collaborators — have surged.
"The organizers of these attacks have the money — and everything in Iraq now revolves around money," said Army Maj. Gen. David H. Petraeus, who heads the 101st Airborne Division in the northern city of Mosul.
A week ago, the Army seized $1.9 million in cash from a suspected insurgent's home in Samarra, a massive sum in a city where the major income comes from Shiite pilgrims to its renowned, gold-domed mosque.
Despite the drop-off in the overall number of attacks, November still featured more coalition fatalities — 111 — than any month since the war began in March, in part because of the crash of four U.S. helicopters under fire.
The psychological toll is such that there is a widespread expectation that the recent lull in Baghdad is a prelude to some kind of major insurgent operation — and there is little that can be done to stop it.
"We either have put a huge dent in their ability to strike in Baghdad," said a senior commander who declined to be identified, his tone revealing some disbelief in that theory, "or they're getting ready for a major attack. It's been too quiet."
Since summer, the insurgents have successfully pushed the front lines beyond the so-called Sunni Triangle in central Iraq to once relatively calm northern cities such as Mosul and Kirkuk, both now awash in attacks and insecurity. Assaults in the largely Shiite south have also thwarted progress and sown uncertainty.
The systematic advance of the insurgent strategy has stunned many U.S. planners, who remain bewildered by the guerrillas' command structure. The walls of Army tactical centers are inevitably filled with charts trying to trace cell members and their links to financiers, known affiliates of Hussein's Baath Party, Fedayeen Saddam paramilitary fighters, hostile sheiks and other suspected subversives.
"The thing that is frustrating still is we're not able to connect what's happening," said Maj. Gen. Raymond Odierno, who heads Task Force Iron Horse, operating out of Tikrit, Hussein's home base.
The guerrilla war has driven the United Nations and most aid groups from the country, while serving notice to countries looking to help that their personnel — military or civilian — would be targets. Coalition-backed mayors and police officers fear for their lives, and U.S. troops must travel only in convoys along roads previously swept for homemade mines and bombs, impeding both the Army's military maneuvers and its civilian aid campaigns.
U.S. civil authorities and their allies are obliged to operate from behind a walled fortress of palaces and offices in the so-called green zone in central Baghdad, isolated from the population they are here to serve.
"That in itself is victory," observed retired British Air Marshal Tim Garden, now based at the Center for Defense Studies at King's College in London.
In timeless guerrilla style, the Iraqi armed opposition appears to have no illusions about inflicting a military defeat on the much larger U.S. force.
"It's not necessary for the insurgents to win militarily," said William Hopkinson, Britain's former assistant secretary of state for policy. "It's sufficient that they don't lose."
Last month, rocket attacks on two major hotels and the Oil Ministry — launched from rickety donkey carts — stole the headlines from Operation Iron Hammer, a much-ballyhooed Army crackdown in the capital. The contrast between the high-tech U.S. approach and the insurgents' primitive but effective strike was unambiguous.
"The enemy has a lower threshold of victory," said Col. James Hickey, a commander in the unstable region near Tikrit. "All he has to do is get on CNN."
U.S. officials put the number of insurgent fighters at 5,000, almost all of them Iraqi. (Army officials say foreign fighters are largely confined to the ranks of suicide bombers.) The insurgents' motivation, analysts say, is an explosive mix of nationalistic, political and religious causes. The estimate of 5,000 excludes a much larger civilian base that can be counted on for additional recruits and logistical support.
In Tikrit, Samarra and other angry towns, pro-insurgency young men gathering to speak with Western journalists inevitably mention the same problems: a lack of economic opportunity, alleged U.S. mistreat- ment and a nationalistic resentment of foreign occupation. Many depended on the former regime for employment, either in the security services or government-run ministries or industries. Now they have nothing.
"What are we supposed to do, starve?" asked one self-described "moujahed" gathered with other men on a roadside in the farming town of Latifiyah, south of Baghdad, where the Spanish intelligence agents were killed last month and the pro-U.S. police chief was killed.
Like others, these men dismissed the notion that their fight will diminish once Hussein is killed or captured, as U.S. officials hope.
"We are not fighting for Saddam," one said.
A menacing wild card in the war is the corps of suicide bombers, mostly believed to be foreign-born jihadis, whom the insurgent forces appear to be able to call on for precision attacks, such as the bombings at the United Nations' headquarters in Baghdad and a strike at Italian military police headquarters in the southern city of Nasiriyah.
"We think they can order up a car bomber when they need one," said Brig. Gen. Mark P. Hertling of the 1st Armored Division, which patrols Baghdad.
With a vast number of U.S. troops scheduled to rotate out after Jan. 1, the Army command has begun to reshape its force — designed for a full-scale ground war — to fit the present, asymmetrical threat. Commanders are stressing a more mobile approach, featuring more light infantry, armored Humvees and fewer tanks and heavy artillery, which have proved of relatively little value in this kind of war.
"The mixes of forces will get adjusted," said Sanchez, the ground commander, who has promised "a very mobile, very flexible, yet lethal force that can accomplish its mission."
The changes reflect a kind of learn-as-you-go approach to a guerrilla conflict that caught the military leadership unawares.
In a report, commanders of the 3rd Infantry Division — which led the assault on Baghdad — said they had won the war faster than expected but "did not have a fully developed plan for the transition" to security operations. The planning has improved at a glacial pace since then, analysts said.
"The U.S. was dismally unprepared for the security mission, armed nation-building and low-intensity warfare when the regime fell," Anthony Cordesman, a military analyst at the Washington-based Center for Strategic and International Studies, wrote in a recent analysis. "It has taken months to make effective changes."
In a page from the counterinsurgency wars of Vietnam and Latin America, U.S. forces are now increasingly turning to the Iraqi Civil Defense Corps to staff checkpoints and perform other tasks that the Army would like to outsource. But the Kalashnikov-toting auxiliaries — typically having only three weeks of training and earning less than $100 a month — have become targets. The situation is so inflamed here in Samarra that civil defense officers posted at the bridge over the Tigris River at the entrance to town don ski masks to hide their identity from fellow residents.