Two days this week of fierce firefights between a Shiite militia and government forces in a usually calm town south of Baghdad left at least 80 dead and an unknown number wounded.
While the top US commander in Iraq said the battle came as a "surprise," it underscores a proliferation of militia groups throughout the country that is making central government control in many places merely notional, many Iraqis and foreign experts say.
The fight in Diwaniyah, 80 miles south of Baghdad, between militiamen loyal to Shiite cleric Moqtada al-Sadr and local forces led by the country's most powerful Shiite parties, demonstrates the growing atomization in Iraq's war. Local politicians, gangsters, and would-be warlords are emerging around the country and taking up arms in service of local ambitions that frequently have little to do with Iraq's sectarian war.
The battle in Diwaniyah, which ended Tuesday when the US Air Force dropped a 500-lb. bomb on what it called a militia position, started just three days after Prime Minister Nouri al-Maliki led a peace conference among tribal leaders designed mostly to undercut Sunni-Shiite sectarian tensions. But, as Diwaniyah demonstrates, sectarian fighting is far from the central government's only security challenge.
"When you say 'civil war' it makes it sound like there are two sides fighting in Iraq,'' says Juan Cole, a professor of modern Middle Eastern history at the University of Michigan. "There aren't two sides – there are lots of sides."
In much of the Shiite south, local leaders increasingly seek to carve out their own fiefdoms and the economic opportunities they generate.
In Sunni provinces, insurgents continue to feed Iraq's sectarian war, as demonstrated by the Sunni mortar attack on a Shiite neighborhood in the town of Khan Beni Saad, north of Baghdad, that drove 30 Shiite families from their homes. And in the contested northern town of Kirkuk, militiamen loyal to the autonomous Kurdish government continue to seek to create "facts on the ground" to press their claims to the oil-rich city.
The most disturbing recent development for the central government may well be the increasing radicalization and splintering among followers of what many Iraqis refer to as the "Sadr stream."
While Mr. Sadr is generally acknowledged as the head of this movement and its Mahdi Army, it looks increasingly as if centralized command and control within the organization is breaking down. That appears to be causing a great deal of confusion and alarm within the Iraqi government.
Sadr's father was Mohammed Sadek al-Sadr, who was killed by Saddam Hussein's regime in 1999. The elder Sadr advocated a militant version of Shiism, and appealed specifically to Iraq's dispossessed Shiite poor with a rhetoric that was equal parts salvation and a call for Iraq's traditional underclass to rise up.
Now, original followers of Moqtada's father are seeking to "out-militant" the younger Sadr on a local basis, jockeying for prestige and control, argues Mr. Cole.
"The Sadr movement has spread like lightning through almost all of the southern provinces'' since Iraq's elections in January 2005, when followers of less militant Shiite Islamist groups like the SCIRI won power in many of these provinces.
"So there's a big disjunction between who has power in the south and the mind-set of the people. Now the Sadrists have so much popular support, but they're locked out of local government and patronage.
"It's essentially a class war. The Sadr guys are pressing ... for a kind of Shiite Maoism. SCIRI represents what's left of the Shiite middle classes," Cole says.
Mahdi Army members in Sadr City, the poor Shiite neighborhood on Baghdad's northeastern edge that serves as Sadr's stronghold, claimed that the fighting was not at Sadr's behest, but also said that some of their ranks went south to participate in the fighting there.
They claimed anger at the recent arrest of a local Shiite preacher who had called for attacks on US forces, and said they felt they had no choice but to fight. "We're the ones resisting the occupiers and the officials who serve them,'' said one, asking that his name not be used. "We're the ones fighting for our people and protecting them. The government is failing."
Nevertheless, Cole and others see economic issues as driving much of the conflict in the south. The deterioration of basic services in the past few years, joblessness estimated at around 60 percent, and rising inflation have left militias squabbling over a shrinking economic pie.
Dominic Asquith, the new British ambassador to Iraq, said that economic stagnation was a crucial component of the collapse of security in Basra in an article he contributed to Al-Sharq al-Awsat newspaper Monday.
"Basra ... until not long ago enjoyed a stable security climate. However, one of the reasons for the unrest is that there has been no perceptible improvement in the quality and extent of the services,'' he wrote. "This has made the Basra residents restless, and led to a band of criminals exploiting such restlessness in order to undermine the stability of the city and provoke sedition."
Even in peaceful regions, Iraqi government control is eroding. In Iraqi Kurdistan, local Kurdish officials allow members of the Kurdistan Workers Party (PKK) – a group fighting for an independent Kurdish state inside Turkey that the State Department has labeled a terrorist group – are allowed to live and infiltrate into Turkey, even though Prime Minister Maliki wants good relations with Ankara and has promised to shut the group down.
Turkey has continued to complain that little has been done against the group, and a week ago, Turkish planes attacked what it alleged were rebel positions inside Iraqi Kurdistan.
• Awadh al-Taaie contributed in Baghdad to this report.