On 22 May, Iraq declared that an operation to retake the city of Fallujah from the Islamic State (IS) terror group had begun. IS militants captured Fallujah early in 2014 before the group moved to seize Iraq's second-largest city of Mosul in mid-May. More than one week on, the Iraqi security forces and supporting Shia militias scored a significant victory in the push to reclaim Fallujah when they recaptured the city's outskirts and brought most of the territory on its fringes under government control. US-led coalition strikes supporting Iraqi forces in the push to recapture Fallujah have reportedly killed dozens of militants, including the group's commander in the city Maher Al-Bilawi. The government also said the security forces had killed, wounded or captured hundreds of others, including many foreign fighters. Despite earlier cautions by US commanders in Iraq that the Iraqi forces' ability to deal a swift blow to IS could be slowed by local support for the militants, the Iraqi government's victory in the Fallujah battle now looks certain. It may even open the door for the security forces to retake Mosul and the rest of the territories still under IS control. The Iraqi army and Kurdish Peshmergas, together with the US-led coalition, are keeping up the pressure on IS in its stronghold of Mosul. However, along with the good news has come scepticism and confusion about the Baghdad government's plans after defeating IS in Fallujah. Located 65 km west of Baghdad, the city has been a stronghold for IS militants who have been trying to break the fragile capital by sowing fear in it through sending in suicide bombers. Iraqi officials believe that many of the car bombs that have exploded in Baghdad recently were loaded and sent by militants in Fallujah, which has a history of anti-government resistance in post-2003 Iraq. This has made many analysts wonder if the battle over the city, which is widely seen by many Iraqi and Arab Sunnis as a bastion of resistance against the Iranian-backed Shia-led government in Baghdad, is really over. One problem already confronting the government is the role of the Iran-backed Shia militias in Fallujah and Tehran's growing clout in the wider war, especially given the presence of the elite Al-Quds Corps commander Qassem Soleimani with Shia forces fighting in Fallujah. Iraqi officials say the militias will not be entering Fallujah and the city's security will be handed over to a local police force and tribesmen when the military operation is over. However, if the militias plan to enter the city and stay in it, such an outcome could prove a fleeting victory because the population in Fallujah and other Sunni-dominated cities will refuse to allow them in, fearing sectarian reprisal attacks. The Sunnis have already accused the Shia militias of sectarian acts in areas surrounding Fallujah, such as destroying mosques, looting and vandalism, though Shia leaders have denied the allegations. On Saturday, the Iraqi Forces Alliance, the main Sunni bloc in parliament, urged Prime Minister Haider Al-Abadi to “spare civilians the scourge of provocative sectarian acts similar to those perpetrated in other [Sunni] cities” in Iraq. The second problem that has already raised the sectarian rhetoric is the high humanitarian cost of the liberation of Fallujah. Many fear the city could face the same fate as other cities recaptured from IS, where the cost of winning the war may be the city itself. More than a week into the military operation to push IS fighters out of the city, hundreds of families have fled Fallujah. The numbers, however, are still very small, given that thousands of people are still trapped inside the city, with some saying they fear being trapped between IS and the Shia militias, two forces they do not fully trust. For months, routes out of the city have been cut off and civilians prevented from leaving by IS militants. Food, clean water, health facilities and medications have been in short supply. Most of the people in Fallujah, which once had a population of 300,000, left the city after it was taken over by IS militants, and now they fear they will return to find their houses seriously damaged or destroyed. Many fear that Fallujah will face the same fate as neighbouring Ramadi, where destruction extended to nearly every part of the city during the fight to retake it from IS earlier this year. Even if the Sunnis may be trying to overemphasise the role of the militias and exaggerate the possible damage they will do, there is no doubt that the war in the city will leave deep scars on Iraq's communal relations. Al Azhar, Egypt's highest sunni Muslim religious institute, has also voiced concerns about the Shia militias' participation in the military operation against IS. Like in Ramadi, widespread destruction could also spark off cycles of revenge attacks within Fallujah's tribal communities. In Ramadi, local officials have reportedly begun systematically razing the homes of suspected IS sympathisers. The big fear now is that of a bounce-back of sectarian reprisals or communal revenge if the government fails to stabilise Fallujah with an effective and credible peace and reconciliation plan. There is also a flip side to the politicisation of the war in Fallujah, which is its manipulation by Iraq's ruling groups for political gain. Al-Abadi, who has been struggling for survival for months amid repeated protests and a spate of terrorist attacks in Baghdad, needs to win and he is trying to show off the military victory in Fallujah as his own success. Emboldened by the military advances, he has allowed the security forces to crack down on the protesters who have been waging weekly sit-ins on Fridays calling for political reform and an increased fight against corruption in his government. On Friday, the security forces fired tear gas as thousands of protesters gathered in central Baghdad and attempted to head to the Green Zone, the fortified central area they have now breached twice. Al-Abadi had earlier called on the demonstrators, most of them supporters of the prominent Shia cleric Muqtada Al-Sadr, to understand that the battle against IS should take priority, but the protesters seem to have sought to underline that reform and fighting corruption are no less imperative than defeating IS. Still, the protests and the failure of the parliament to resume its sessions for lack of a quorum signal a wider Shia power struggle that is expected to intensify after the dust of war has settled. Meanwhile, the battle over Fallujah has evolved into yet another example of how many stakes Iraq's neighbours feel they have in Iraq. These neighbours, who have been embroiled in a full-scale stand-off over Iraq since 2003, are now making Fallujah into a new political battlefield. The participation of Shia militiamen alongside the Iraqi armed forces in the Fallujah operations has sparked fears in neighbouring countries that Iran and not the Iraqi government has become the face of the operation to retake the city from the militant Sunni group. Saudi Arabian Foreign Minister Adel Al-Jubeir has accused Iran of interfering in the internal affairs of Iraq, saying on Sunday that Iran must stop meddling in Iraq and that the presence of Iranian military units there is “unacceptable.” United Arab Emirates Deputy Foreign Minister Mohamad Al-Mazroui told a meeting of the anti-IS international coalition in Berlin that “only the Iraqi army, police and local tribes should participate” in the fight to take back land now under IS control. Al-Azhar, Egypt's highest Sunni Muslim religious institute, has also voiced concerns about the Shia militias' participation in the military operations against IS. Though both Iraqi and Iranian officials have said that Soleimani is in Iraq at the request of the Iraqi government, the squabbles over the Shia militias and Iran's role have increased the tension in the region. Reflecting these concerns of sectarianism and the deep sense of symbolism attached to Fallujah by local and regional stakeholders, the liberation of Fallujah and the other Iraqi cities from IS could prove to be a double-edged sword for the future of Iraq. A lot depends on whether the Baghdad government has been working out plans to cultivate the peace after winning the war against IS. This should include ending the root causes of the problems that led to the terror group's debacle. A lot also depends on Iraq's neighbours, whose rivalry has helped stoke sectarian mayhem and poisoned Sunni-Shia relations more widely in Iraq. They should stop vying for influence and interfering in Iraq by fuelling sectarianism and deepening distrust between Iraqis.