One is Sunni, one Shia and one Christian. They have been crammed together for years in a small agricultural supplies store and showroom in central Baghdad’s vast Senek Market.

Outside the sprawling maze of 1,000 businesses, Iraq is alive with talk that the country might be split into Sunni, Shia and Kurdish states to staunch the bloodshed of sectarian violence. Inside the bazaar, despite an anti-government insurgency in the Sunni heartland and a renewed drive for independence by Kurds, many cannot countenance the notion.

“If you come to the question from the perspective of this market, Iraq will work,” says Majid Mikhail, 55, a Christian. Ahmed Shaker, 35, a Shia, agrees. “Iraq is one beating heart,” he says. But Ahmed Saleh, 44, the Sunni, is not so sure. “In these circumstances, maybe it would be better to have a Sunni homeland,” says Mr Saleh. “The problem is the majority of people are ignorant, and that’s where you find sectarian violence.”

Senek, a name derived from the Ottoman word for the flies that once infested the area, is Iraq’s central wholesale market for industrial goods. Merchants from across the country haggle with importers before trucking purchases back to their shops scattered across Iraq’s 18 provinces.

“There is no place here for sectarianism,” says Yahaa Mandalawi, a 60-year-old Nissan parts distributor. A native of the diverse province of Diyala, he lives now in a religiously mixed neighbourhood in the capital. Both his daughters have married into a different sect. “Our people have coexisted for a long time.”

Only Iraqis grasp how intimately the lives of the country’s communities have been woven together, how intricately relations within clans and families have been entangled – and how tortured would be a sectarian divorce. Many tribes include both Sunni and Shia branches, and intermarriage continues to be common.

Sheikh Abdullah Hamad al-Anbari, the leader of a largely Shia tribe, illustrates how intimately the different groups are intertwined. “My tribe is named after them,” he says of the Sunni Anbar province, which today is largely under the control of Sunni militant groups. Among them is the Islamic State of Iraq and the Levant, known as Isis, which has made redrawing Iraq’s borders – created by the Sykes-Picot agreement of 1916 – a core mission.

Iraqis are also bound together in a union of shared suffering that includes the trauma of the Iran-Iraq war, the punishing western sanctions that drove many into poverty during the 1990s, the terror of the US-led invasion and subsequent bloody spasms of the country’s civil war.

A separation of any kind, whether a formal redrawing of the map as demanded by Kurds or the creation of a separate Sunni homeland as proposed by some Sunni, would be so painful that some spurn it outright. “My mother is Sunni, my father is Shia and my brother married a Christian,” says Sabine Awad, a 26-year-old who works in Baghdad’s Mansour district. “We are all brothers and sisters. We cannot separate.”

But, underscoring the depths of the crisis, many imagine a partition of Iraq, a land of constant war, ubiquitous weapons, rampant corruption and broken public services.

“The problem is not just security or politics at this point – half of the country is already out of the control of the government,” says Thamer Tamimi, an adviser to Nouri al-Maliki, the prime minister “It’s too late for Iraq,” he says with a sigh.

Slow collapse

Despite paeans to national unity, Iraq has been disintegrating for decades. The Kurds spent much of the past century in armed revolt against successive Arab governments in Baghdad before securing autonomy in 1991. Outside the relatively cosmopolitan capital, large segments of the country’s Shia population were locked in armed confrontation with the government since Saddam Hussein consolidated his power in 1979 until he was toppled by the US in 2003.

Within weeks of the US invasion, a Sunni insurgency flared up against the Americans and then the Shia majority now dominating the country. “The sectarianism has been here for a long time; it’s not new,” says Ziad Ajeel, a political analyst. “The Kurds refused to be ruled by the Arabs. The Shia refused to be ruled by the Sunni. Now the Sunni don’t want to be ruled by the Shia. Iraq’s history confirms that you cannot achieve your rights without the use of weapons. And that is the problem with Iraq.”

Neighbouring Syria, with its ethnic mix of Kurds, Sunni and Shia that mirrors that of Iraq, is also falling apart. There is a sense that Iraq’s demography is incompatible with the zero-sum politics that have long dominated the country and region. All three of Iraq’s main communities view themselves as aggrieved victims of history as they absolve themselves of their own sins.

“Saddam Hussein did the same thing to the Shia that Maliki is now doing to the Sunni,” says a 23-year-old Sunni man in Adhemiya district.

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Outraged by their treatment at the hands of the Shia government, many Sunni began agitating for a federal region months ago, led by Osama Nujaifi, the outgoing speaker of parliament who heads one of the main Sunni political blocs.

In cafés, on television and in newspapers, many speak of a future Iraq with Sunni inhabiting their own region, much like the Kurds. Iraq’s Kurds fly their own flag, assemble their own armed forces and run their own schools with little interference from the Baghdad government.

“The missing component in all of this is loyalty to Iraq,” says Qubad Talabani, deputy prime minister of the Kurdistan Regional Government. “That’s what makes me less optimistic about the country’s future. We’re not seeing loyalty to Iraq. We’re seeing loyalty to different sects, to ethnic identity, to religious ideologies.”

A messy divorce

Nothing in Iraq is so simple as drawing lines on a map. Many of its provinces are mixed Sunni and Shia. Diyala, northeast of Baghdad and abutting both Kurdistan and the Iranian border, includes Shia and Kurds as well as the majority Sunni.

While the mostly Kurdish eastern end of the province around Khaneqin could be incorporated into the Kurdistan region, the western half of the province is a patchwork of Sunni and Shia towns, which makes cutting a line through it impossible.

Within at least two Shia provinces – Babel, just to the south of Baghdad, and in Basra in the deep south – there are several significant Sunni districts. There are also Shia districts in other provinces, including several Shia Arab and Turkoman enclaves.

Just as Arabs live amicably within the autonomous Kurdistan Regional Government, Sunni could in theory live amicably in Shia areas. But for now mistrust runs too high.

“If a Shia guy goes to a Sunni area, he will be slaughtered,” says Seitar Jalil, 42, a carpenter in the Shia city of Najaf. “But if a Sunni comes to our areas, we welcome him.”

Baghdad itself may be the most complicated piece of the puzzle. Although once fairly equally divided between Sunni and Shia, the city has lost up to 60 per cent of its Sunni over the past decade. Many neighbourhoods are mixed. Few believe that the Shia will let go of any part of the capital, which is also coveted by the Sunni.

Iraqis have long considered the Rasafa area of Baghdad east of the Tigris river a Shia bastion. The western half, called Karkh, was dominated by the Sunni. But the shrine of Imam Kadhem, one of the most important in Shia Islam, lies in Karkh, while the most important Sunni mosque in the country, Adhemiya, lies on Shia side of the river.

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“As a very last resort, one may be able to move the sarcophagus of Imam Kadhem from west to east, and solve the problem,” says Mazen Mohamed, an actor who has spent entire evenings struggling to map a future Iraq with other intellectuals. “But this is a very sad conversation.”

Any Sunni entity in Iraq could quickly descend into infighting, especially between the large Dulaymi clan of Anbar and the Shammari tribe of Nineveh. “Those of Anbar will want Ramadi as a capital and those of Nineveh will want Mosul,” says Adnan Hussein, editor of al-Mada newspaper. “There is a lot of bad blood between the tribes.”

Fighting has already broken out between Sunni rebel factions. Few believe a compromise is possible between radical Islamists seeking to establish a utopian version of the caliphate and whiskey-swilling members of Saddam Hussein’s former Ba’ath party keen to throw off the yoke of Shia rule.

Outright partition of Iraq’s three main Sunni provinces simply may not be feasible economically. Much of Anbar, Salahadin and Nineveh provinces are sparsely populated, landlocked and devoid of natural resources. “Sunnistan is the poorest portion of Iraq,” says Wayne White, an Iraq specialist formerly at the US state department and now at the Middle East Institute in Washington. “Its agriculture is nil. It has no oil. It could be a new poverty-stricken Middle East state. Backing themselves into a dry, landlocked, barren and oil-poor corner of the country wouldn’t be exactly desirable.”

Even if oil is discovered, a landlocked Sunni statelet lacking a strong strategic partnership with its neighbours may never thrive. As South Sudan has shown, having an oil-rich country with little else is hardly a recipe for success. “If you’re going to be economically viable you have to have some kind of agreement with your neighbours for stability,” says Sijbren de Jong at The Hague Centre for Strategic Studies in the Netherlands. “Exporting anything depends on getting access to ports, networks of pipelines, infrastructure.”

The Shia would also be likely to resist a Sunni entity that controlled the upper Euphrates and Tigris rivers, the main sources for agriculture in the south.

An orderly separation

Partitioning Iraq now, whether into federal regions or separate statelets, could be disastrous. Tempers must first be cooled and Isis must at least be isolated if not defeated outright.

It may require a new government without the divisive Mr Maliki. Politicians and opinion makers float several ideas for rebooting Iraq. Article 140 of the constitution permits provinces to coalesce into single regions, capable of governing their own affairs. That has been discussed for Nineveh, which encompasses Mosul, Salahaddin and Anbar provinces.

National security, foreign policy, oil revenues and border control would all fall under the purview of the central government.

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“Though it’s not yet time to start redrawing borders, there is an option available, which is true federalism or confederalism,” says Mr Hussein. “We expect difficult times ahead and a lot of bloodshed, but we might be able to avoid the worst if there is some kind of regional federalism. The Kurds might even accept confederalism or even federalism.”

Nabeal Younes, a political scientist an adviser to Mr Nujaifi, suggests dividing Arab Iraq into three regions: one for the Sunni, one for the Shia and one mixed central province that includes Diyala, Baghdad and all the heavily mixed districts around it.

Kurds aside, opinion polls show that Iraqis do not want their country broken up. A 2009 petition to hold a referendum on turning parts of the south into a separate region failed to attract enough signatures. The ideal of Iraq as a mosaic of different religions, tribes and languages epitomised by the Senek market still carries much weight.

But in recent weeks, momentum has built for a drastic reconfiguration as the least bad solution. Despite their best intentions, it may no longer be possible for Sunni and Shia to live together. “If the government can’t protect Sunni as citizens or doesn’t protect us as citizens, we are going to go out on or own,” says Mr Younis.

Memories of the sectarian civil war, which in 2006 and 2007 left 100 corpses a day in the capital’s morgues, linger just beneath the surface. “The militias started killing people,” says Munther Abdul Ghani, 75, a retired schoolteacher in the religiously mixed Baghdad district of Sadiya. “And they killed my son.”

In the mostly Sunni Ghazaliya neighbourhood, Shia militias and members of Mr Maliki’s “antiterrorism” forces cruise the streets nightly, menacing locals with chants commemorating the seventh-century martyrdom of Hussein, grandson of the prophet Mohamed, at the hands of the Sunni caliph.

“We don’t refuse to live under the Shia; they are our brothers. I have family ties to Nasiriya,” says Raed Kamel, a lawyer and member of the mostly Sunni Dulaymi tribe in Ghazaliya. “Here, we don’t speak of Isis. We only speak of the many injustices that caused the Sunni to rise up. Before we refused to consider a Sunni region as a solution, but after the injustices that have befallen us, maybe it’s for the best.”

Additional reporting by Erika Solomon in Erbil