Turi Munthe, a regional expert at the Royal United Services Institute in London, puts the dilemma this way.
"It's a little bit of a lose-lose situation. I mean, you can start reconstruction projects after everything has been destroyed, and it is clear you are the ones who destroyed it. [But] it is going to be a very complex situation. On the other hand, how long are you going to sit and wait to try to work out whether negotiations will ever go anywhere?" Munthe asked.
In describing their reasons for using force, U.S. and Iraqi officials have argued the high cost of doing nothing after efforts to settle the Al-Fallujah crisis by negotiation collapsed.
In those talks, government officials had demanded that Al-Fallujah's civic leaders expel foreign fighters and other insurgents from the city and hand over all heavy and medium-sized weapons. Baghdad also had demanded that civic leaders allow officials to begin reconstruction projects that could help pacify the city.
But delegations from Al-Fallujah -- including tribal notables and clerics -- argued that most fighters had already left the city, making it impossible to meet the demands. The government said that left no option other than military action.
But analysts say the government's choice to use force in Al-Fallujah comes with no guarantees of long-term success.
One risk is that many insurgents may have already left Al-Fallujah and could reconstitute their forces in other central Iraqi towns.
Mahmud Uthman, an independent Kurdish analyst and member of the former Iraqi Governing Council, says that is a pattern already seen in earlier face-offs between security forces and rebels.
He cites recent events in the central town of Samarra as an example.
"[U.S. forces] made operations in Samarra, they controlled Samarra and everybody said the Americans are there, the Iraqi government has Samarra under control. And then you saw what happened just two months after they controlled Samarra completely, even less than two months. Again, the insurgents are there because when [U.S. forces] make an operation in one town, they say they are encircling it because they are cutting the main roads. But many insurgents get out of town. Then when the operations are finished, [insurgents] come back," Uthman said.
Last month, American and Iraqi commanders ended an operation to re-establish government control in Samarra. Allawi called the operation a model for wresting key areas of Iraq from insurgents before the election.
But the extent of government control in Samarra was called into question on 6 November when suicide bombings and attacks on police stations killed 34 people. Most of the victims were members of Iraq's security forces.
Beyond the risk of scattering Al-Fallujah's insurgents elsewhere, there are fears that the assault on the city could result in numerous civilian deaths, creating a backlash of public opinion against the government.
An early sign of this came today when one leading Sunni Muslim political party -- the Iraqi Islamic Party -- pulled out of the interim government.
Mohsen Abdul Hamid, a senior party official, told reporters in Baghdad that the party has decided to withdraw from the government in protest against the attack on Al-Fallujah, which he said is "harming the people."
A separate influential Sunni group that has not participated in the interim government urged Iraqi security soldiers yesterday not to fight alongside U.S. troops in Al-Fallujah.
The Association of Muslim Scholars said in a statement reported by the Arabic satellite channel Al-Jazeera that Iraqi soldiers must "beware of making the grave mistake of invading Iraqi cities under the banner of [U.S.] forces who respect no religion."
The movement of radical Shi'a cleric Muqtada al-Sadr also condemned the Al-Fallujah operation today. Al-Sadr aide Abdul Hadi al-Darraji said: "We condemn this attack that will escalate the security situation inside Iraq."
Loyalists of al-Sadr fought against U.S. troops in Baghdad, Al-Najaf, and elsewhere in April and August before truce deals brokered by top Shi'a religious leaders.
Analyst Munthe says the most difficult battle the government will have to fight will come only after military operations in Al-Fallujah and elsewhere end. He says that battle will be to persuade people in the region that they should participate in the January vote, despite strong local propaganda not to do so.
"There has been enormous amounts of propaganda in Al-Fallujah and the Sunni Triangle, saying that democratic elections are designed exclusively to oust the Sunnis from any kind of power at all. And the biggest battle is going to be to get people to vote. Now clearly, one large part of that battle is to ensure that they can safely get to vote without being blown up in their queues. But another part of it is clearly a psychological operation, some battle to reinstall faith [in the electoral process] in the Sunni regions," Munthe said.
In that psychological battle, the government will continue to face a determined foe from a disparate mix of militant groups who oppose efforts to build a new Iraqi order.
Those groups include loyalists of Saddam Hussein who claim the Sunni community is being deprived of its former privileges in favor of Iraq's Shi'a, Kurdish, and other communities.
The insurgent groups also include extremist Islamist groups with foreign fighters and self-declared "nationalist" groups opposed to the U.S. occupation of the country.