Prime Minister Nouri al-Maliki is poised to unleash his army in a major offensive to recapture the western city of Fallujah seized by al-Qaida forces Dec. 30 in what's widely seen as the greatest challenge to his increasingly autocratic Shiite regime.

But there are fears his efforts will only intensify growing opposition from Iraq's Sunni minority, which he has been systematically marginalizing for the last three or four years, spurring the resurgence of al-Qaida, which U.S. forces had decimated before their withdrawal in December 2011.

"Within Iraq, al-Qaida's resurgence is making the country less stable and cohesive, splitting apart Sunni and Shiite power bases while Iran's influence grows stronger," Iraq specialist Michael Knights of the Washington Institute for Near East Policy told the U.S. Congress in December.

Maliki has vowed to send in his U.S.-trained, Shiite-dominated military to retake Fallujah, a Sunni stronghold in western Anbar province that borders Syria.

But, at U.S. urging, he's stayed his hand, saying he wants to avoid heavy civilian casualties and to let the Sunni inhabitants and local tribes expel the jihadist fighters.

However, analysts say al-Qaida forces holding Fallujah will not abandon the city 50 miles west of Baghdad, the first major population center the jihadists have wrested from a central government they believe is heavily influenced, if not controlled, by Tehran.

"The government will try to expel al-Qaida militants from Fallujah with a combination of military pressure and tribal mediation," Oxford Analytica predicted.

"There is a considerable risk that Baghdad will make political and military errors during the operation that will further alienate Sunni Arabs, exacerbating Iraq's security crisis."

"They'll only enter Fallujah over our dead bodies," declared Khamis al-Issawi who said he was with a 150-man al-Qaida brigade that helped seize Fallujah. "We're ready and prepared to fight."

Maliki faces parliamentary elections in April and he will want some military victories under his belt to boost his prospects for a third term.

He failed to win an outright victory in the 2010 election and it took him months to stitch together an uneasy Shiite-dominated government that shunned the Sunni minority, which had been a pillar of Saddam Hussein's brutal regime.

He'll need to secure a convincing win this time, but it remains to be seen whether he'll embrace Sunni politicians to demonstrate the minority will have a stake in policymaking.

In recent weeks, Maliki has made what were initially perceived by observers as political blunders, particularly a series of blatantly anti-Sunni rants. Some observers now suspect he may even have been intended to trigger unrest.

"Maliki's running an increasingly overt sectarian election campaign, and this is part of it," noted Toby Dodge, a veteran Iraq observer with the London School of Economics.

"He needs to solidify the Shiite vote before the election, and the bigger the al-Qaida threat, the better the chance he has of doing that."

Going soft on Sunnis won't go down well with majority Shiites who've suffered grievously from al-Qaida's depredations, particularly suicide bombings, in recent months.

The Sunnis have been in open revolt since April 2013 when Saddam's troops gunned down scores of protesters in northern Iraq demonstrating against his purge of Sunni politicians accused of terrorism.

The subsequent wave of unrest, particularly in the Sunni strongholds of Anbar, Salahuddin and Diyala provinces, has left Maliki grappling with a populist revolt and a militant insurgency.

Al-Qaida leader Abu Bakr al-Baghdadi, a veteran jihadist, launched a "Destroying the Walls" campaign against Maliki's military forces July 12, 2012, aimed at weakening the regime's authority.

After the jihadists assassinated the commander of the army's 7th Division, a major general, and 18 of his senior officers in an elaborate multiple suicide bomb trap Dec. 21 in the western town of Rutbah, Maliki responded with a severe crackdown that played right into al-Qaida's hands.

At least 44 Iraqi lawmakers resigned in the wake of the killing of 13 Sunni protesters and the arrest of a prominent Sunni legislator in the region.

Al-Qaida exploited that surge of anti-government anger to storm Fallujah and Ramadi, Anbar's provincial capital, in their most direct challenge to Maliki since the U.S. withdrawal.

"It should be clear that Iraq cannot kill its way out of this crisis, though Baghdad may find this option an alluring misconception," Knights observed.