For days Isis militants have clashed with Peshmerga in the scorched Nineveh prairielands near Mosul.
The fighting, notably in the Christian village of Karakosh - Nineveh is home to many Assyrian Christians who have fled persecution elsewhere in Iraq - sent waves of people scurrying for cover, emptying villages, while raising fears that Iraq's Kurds are being sucked into a conflict of which they want no part.
"We are afraid," says Osama, who did not want his last name used. "They will kill anyone who doesn't think like them."
For the past two weeks Isis - buttressed by disillusioned Sunni from Anbar province - has carved its way through a massive expanse of land, taking cities, villages and border crossings as it seeks to topple the Iranian-backed Government of Nouri al-Maliki in Baghdad and establish an Islamic caliphate in Iraq and neighbouring Syria.
As Isis advanced, the Kurds sealed their lands while expanding into territory they dispute ownership of with Baghdad and which Iraqi soldiers abandoned in the face of the Isis surge. In doing so, a mutable and volatile border, stretching hundreds of kilometres, separating the Kurds and Isis was established.
Fiercely nationalistic and with a strong secular current, the Peshmerga have been widely praised for protecting northern Iraq's many different sects - Christian, Yazidi, Shia, Shabak - as the Takfiri militants of Isis, for whom killing "non-believers" is a core ideological component, sweep across the deserts.
Isis evolved out of al-Qaeda's formal Syria affiliate, Jabhat al-Nusra, after a power struggle last year, and quickly became notorious for its brutality: decapitations and a series of crucifixions.
In one video, a woman sits on her knees, a hijab pulled close about her face. An Isis fighter, adorned in black robes, stands behind her. He wraps cord around her neck.
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The militant draws the cord tight and within a minute she is dead. The execution, shot on a video camera in Manbij, in rebel-occupied northwest Syria, is but one of a slew of recordings highlighting the group's brutality.
"Isis are terrorists and filth," says Orhan, a Kurdish policeman, who would provide only his first name, sitting on the outskirts of Karakosh, as nearby Peshmerga send 120mm mortar bombs arcing through the skies into Isis positions across town.
Displaced persons drift along roads. The charred shells of previous car bombs sit wasted in ditches.
The Kurds have long dreamed of establishing an independent homeland, having been denied a state as the British and French carved up the Middle East following the Ottoman collapse.
With the capitulation of the Iraqi military to Isis fighters, they may now be closer to it than ever before.
"The time is here for the Kurdistan people to determine their future and the decision of the people is what we are going to uphold," Kurdish President Masoud Barzani told CNN last week, as US Secretary of State John Kerry made an impromptu visit to Erbil, calling for Kurdish support to halt the dissolution of the Iraqi state.
However, Iraq is a volatile place, even in the relatively secure Kurdish areas.
On Wednesday a suicide bomber wandered into an arms bazaar in oil-rich Kirkuk, which the Kurdistan Regional Government took control of two weeks ago and views as the jewel in the crown of any Kurdish state.
The bomber detonated an explosive vest. Among the dead was a 10-year-old boy. A day earlier, gunmen blasted bullets through a local Turkmen politician's head. He was distributing aid from Turkey.
At street level, both attacks were widely interpreted as an attempt by Maliki's Government to destabilise Kurdish areas - setting aflame the delicate sectarian and ethnic fabric of Iraqi Kurdistan, in a city which has been contested by Arabs and Kurds for 70 years - in the event that Kurds decide to separate from Iraq.
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Regardless, observers note it is unlikely that Baghdad will be able to reassert control over Kirkuk any time soon.
At the site of the car bombing, the road is closed, and traffic is mounting. People step from their cars, trying to catch a glimpse of the smouldering ruins.
"They come here and blow themselves up," says Osama. "How can you fight this? How do you fight a group that has no rules?"
