After more than nine months of political deadlock, Iraq has a new national unity government, divided among the country's many competing ethnic and sectarian factions, including Sadrist politicians. The BBC's Gabriel Gatehouse in Baghdad reports on the growing fears that the return of the Sadrists is triggering in the Iraqi capital.
Prime Minister Nouri al-Maliki has indeed had to reconcile the seemingly irreconcilable - his government includes the likes of Saleh al-Mutlaq, a Sunni politician banned from the election in March for alleged Baathist connections, and a number of Sadrist MPs, followers of the staunchly Shia cleric, Moqtada al-Sadr.
Some of Iraq's key ministries have been left unfilled, notably the three security ministries - defence, interior, and national security - because Iraq's rival factions are acutely sensitive to any suggestion that the country's armed forces could be used to promote sectarianism.
The decision seems to have been a necessary compromise to get a new government voted through before the constitutional deadline of 25 December.
But even before the cabinet was announced, Mr Maliki's temporary stewardship of the security ministries was coming under fire - notably from the Sadrists.
'People are scared'
It was the unexpected support of Moqtada al-Sadr, announced in October, that enabled Mr Maliki to hold onto the top job.
As recently as 2008, the Iraqi security forces, under the command of Prime Minister Maliki, did battle with Mr Sadr's feared Shia militia, the Mehdi Army.
Though both sides deny there was a deal, members of the Mehdi Army have been released from jail in recent months, bringing back bad memories of sectarian violence, and spreading fear on the streets of Baghdad.
In Kifah street, in the centre of the city, we met Alaa Abbas, manning a checkpoint with some colleagues.
The area is a mixed Sunni-Shia neighbourhood, known for its wholesale tobacco market.
During the years of sectarian violence, gangs of kidnappers and killers would roam this neighbourhood, snatching people off the streets, sometimes never to be seen again.
Then the government started clamping down on the militias.
Alaa Abbas and his men were hired to make these streets safe again. They were personally responsible for putting Mehdi Army members behind bars.
Now, Mr Abbas says, many have been released, and he and his men are afraid for their lives.
"They used to come to our area, to kill, kidnap and rob people," he says as he looks nervously round the street.
"We kicked them out of here. But now we are back to square one. People are scared. We will all get hurt. We could get killed in the street, because we fought against them."
The Mehdi Army was a formidable force, fighting the Americans and also acting as a Shia militia force during the worst of the sectarian violence in 2005 to 2007.
In early 2008, Prime Minister Maliki sent in the Iraqi military to clear the Sadr militia from its strongholds in Basra, Baghdad and elsewhere.
After months of fighting, the Mehdi Army agreed a ceasefire, and Mr Sadr officially ordered the militia to lay down its weapons.
Some thought Mr Sadr had been defeated, that his power, which had risen so suddenly and with stunning speed after the US-led invasion in 2003, was on the wane.
These days the Mehdi Army does not carry guns on the street any more.
But in strongholds like Sadr City in Baghdad, they are easily identifiable by their black shirts.
Here, on a Friday, Moqtada al-Sadr's resurgent power is obvious for all to see.
A group of men, carrying coffins on their shoulders and chanting songs and slogans, parade a life-sized photograph of Mr Sadr through the streets.
His picture is on show in other parts of town too. Just a few months ago, such displays would have been unthinkable. But now things are different.
One of the pall-bearers, another man in a black shirt who didn't want to give his name, said those coffins contained two Mehdi Army members, killed in a recent bomb attack.
"Yes, many of our members have been released," he said. "But many others are still in detention, either by the [US] occupation force, or they are detained in Iraqi detention centres."
At the start of Friday prayers, the imam read out a message from Moqtada al-Sadr, urging his followers to march in support of a decision by Baghdad city council to close down many alcohol stores and nightclubs.
Mr Sadr's exact whereabouts is a secret, though he is widely believed to be studying in Iran.
His top representative in Iraq, Hazim al-Araji, says the Mehdi Army is now dedicated to achieving its aims through peaceful means.
"We did not order our followers to burn or attack those places, but we told them to hold a peaceful demonstration," he said, dressed in a black turban and black robe.
"Our duty is to propagate virtue and prevent vice without using force. Now is not the time to use force."
There are no official figures for the number of Mehdi Army members released in recent months. Estimates range from dozens to hundreds.
And like the Iraqi government, Hazim al-Araji denies that there was ever any deal to let these men out of jail in return for political support from the Sadrists.
But there seems to be a threat implicit in the cleric's words.
As Moqtada al-Sadr's followers gain in strength and confidence, the fear is there could yet come a time when the Mehdi Army will take up its arms again in pursuit of its strict moral and political aims.
Mr Maliki's new government will have to face a number of urgent issues - continuing instability and violence will be priorities, as will trying to pass a long-awaited hydrocarbon law to divide up Iraq's lucrative oil revenues between the various regions.
This issue is likely to cause tensions with the Kurdish bloc in parliament.
Another controversial question that needs addressing is - what to do about the Americans?
Under the current Status of Forces Agreement, all US military personnel must withdraw from Iraq by the end of 2011.
The US has quietly let it be known that it would be open to the idea of keeping a number of troops in Iraq after that deadline - but only if requested to do so by the Iraqi government.
Until now, the government has shown no sign of asking them to stay. And the Sadrist presence at the cabinet table would make such a request politically difficult for Mr Maliki.
The Sadrists regard the US military as an occupying force. Indeed Hazim al-Araji told the BBC that the one area where the militia still engages in military activities is in fighting the US presence in Iraq.
"We seek to force them out, even before 2011. So [the idea of their] staying beyond the date set by the security agreement cannot be tolerated."
"We have called for the withdrawal of the occupation force and we continue to call for that."
Putting together this national unity Government may have been a "most difficult task" by Mr Maliki's own admission.
But he could find that there are trickier times ahead, as he tries govern his unwieldy coalition.