IT’S been a few months since I was last in Iraq. For some time now the bitter battle for the country’s second largest city, Mosul, has preoccupied much of my journalism. As the jihadist Islamic State (IS) group fights for its very survival in the warren of narrow streets in the west of the city, some are already dubbing its stand the death rattle of the group’s self-proclaimed caliphate.

Arriving on Tuesday I almost expected to hear echoes of that rattle the moment I stepped from the plane into the comparative safety of Erbil, capital of Iraqi Kurdistan. Erbil, after all, sits only a little farther from Mosul than Glasgow does from Edinburgh. Though both cities exist within the cauldron of war, they remain worlds apart. If Erbil nestles on the very outer rim of that cauldron then Mosul occupies its dark core. To travel the short distance between the two places is to witness a metamorphosis of landscape. While Erbil has the chaotic, life-affirming energy of a Diego Rivera mural, Mosul right now resembles the deathly apocalyptic medieval vision of Hieronymus Bosch.

In Erbil, you have to look closely for the influence and effects of the war making global headlines a few miles west. On the city’s fringes, armed Kurdish Peshmerga fighters man checkpoints and flag down vehicles for ID spot checks of those on board.

In the shopping malls, metal detectors are mandatory and customers can expect a frisking from security guards looking for the guns and bombs that are ubiquitous among the IS sleeper cells known to exist within the city. Elsewhere on Erbil’s streets, the human flotsam forced to flee their homes because of the Mosul maelstrom can occasionally be seen begging. Many have the haunted look of those who have already seen too much. It’s almost as if the images in their heads have already turned to black and white, menacing monochrome memories that most of us can scarcely imagine.

It was the sight of a familiar figure that caught my own attention at my hotel over breakfast on my first day back. At first, I was unsure if it was the same man, having never seen him in uniform before. Tall, wiry with blonde hair, Christophe is not an Iraqi, but a Frenchman. Last October he arrived here, looking to join the fight against IS as a volunteer with the Kurdish Peshmerga. In the interim he had evidently made their ranks, the flag of Kurdistan shoulder patch on his camouflage fatigues confirming as much. It was perhaps hardly surprising for a former French commando.

Christophe is one many foreigners who felt compelled to come here and confront the jihadists of IS who themselves have volunteer overseas fighters, some of them British. “Welcome back,” he greeted me, before telling of how he and a few fellow “French Peshmerga,” were likely heading to Mosul in the coming days. Their job, he said, was to take up the near-suicidal task of helping clear the countless mines, booby traps and roadside bombs IS has left in its wake.

It took the Iraqi Army and Kurdish Peshmerga three months to conquer the eastern side of the city, and casualties were heavy. Behind them IS has left ruination, the university destroyed, libraries burned and a city festooned with tunnels and improvised explosive devices (IEDs).

If this battle has taught the world anything about the jihadist cause it’s what happens when a seventh century philosophy marches hand-in-hand with 21st century technology. In a twisted interpretation of religion, drones are unleashed to drop grenades and suicide truck bombers sent on their deadly mission on an industrial scale.

IS created special schools and indoctrination centres where suicide operations are promoted as the “quickest and easiest path to paradise”. “My dear family, please forgive me,” reads one handwritten letter found discarded in the dusty halls of an IS training compound in eastern Mosul. These were the parting words of schoolboy Alaa Abd al-Akeedi before he set off from the compound to end his life in a suicide bomb attack against Iraqi security forces last year. “Don’t be sad and don’t wear the black clothes (of mourning). I asked to get married and you did not marry me off. So, by God, I will marry the 72 virgins in paradise.”

Mosul itself, meanwhile, could not be further from paradise. The battle for its heart has served as another reminder of mankind’s capacity to commit unspeakable atrocities. Outside the city’s limits off the Baghdad-Mosul highway a landmark known as the Khasfa sinkhole is said to have swallowed the mutilated bodies of IS enemies since it captured the city in 2014.

Once 400 metres deep, it has now been filled with perhaps as many as 4,000 corpses. It was this story that Kurdish journalist colleague Shifa Gardi was trying to cover when she was killed by a roadside bomb last week. She wanted to cast light on tthe IS brutal reign that has included mass executions and the enslavement of thousands of women from the Yazidi minority, among other atrocities.

Right now the battle for the western half of Mosul continues. Upwards of perhaps a quarter of a million civilians remain trapped in the city, many of them used by IS as human shields in an effort to stop the advance of Iraqi forces. Those who don’t comply are more often than not executed. Those civilians who try to escape the fighting are often killed by coalition airstrikes, suicide bombers, and by IS snipers, who deliberately target them as they flee toward government forces. This morning, after writing this, myself and a colleague will set out in search of this latest stream of desperate humanity who have fled eastwards.

Many questions remain about what post-IS Mosul will look like. No one knows when the city and Iraq’s agony will end, or what will be the long-term outcome once the jihadists are defeated in the city. The rise and fall of IS has sharpened and focused the divisions in Iraq, instead of healing them. Many fear for yet more sectarian instability and that the past may yet come to haunt Mosul in the future.

The death rattle of IS in its self-proclaimed caliphate becomes louder by the day, but still the jihadist presence stalks Mosul and will likely do so for months to come. This latest assignment is only just beginning. It will not be the last in Mosul or Iraq. Peace sadly remains as elusive as ever in this long-suffering country.