Amid the wreckage, though, are the signs of new arrivals – forces who less than a week earlier chased Islamic State (Isis) from one of its most important territories in northern Iraq.
Spraying graffiti and planting their battle colours, they have wasted little time in staking their claim to a place that had mattered little in the sweep of Iraq’s modern history, but which is set to be pivotal from this moment on.
Ba’aj is now a foundation point of an Iranian plan to secure ground routes across Iraq and Syria and into Lebanon, cementing its influence over lands its proxies have conquered.
“From Mosul to Ba’aj, thank you Suleimani,” read one message painted on the town roundabout in tribute to the Iranian general Qassem Suleimani, who helped lead units of the Popular Mobilisation Front (PMF) as they swept through Ba’aj toward the Syrian border. Flags of various Shia units were planted like poppies.
On the road into town, Abu Mahdi al-Muhandis, the joint leader of the PMF, was greeting his victorious forces who in recent weeks have carved out a new swath of influence from Mosul to the Syrian border.
“This was the last castle in the area for Isis, said Muhandis, in a rare interview inside a tribal meeting hall his men had commandeered. “It was the crossing point for terrorists from Turkey since 2013-2014. They entered Ba’aj and Tel Afar. It’s a strategic area for their leaders.”
Along the highway from Qayyara to the south of Mosul, diggers, roadwork machines and bulldozers are lined up. Some will join the Shia-dominated units in battle as they push the retreating ranks of Isis into Syria.
Others will soon be used to consolidate what has been left behind, a barely passable network of roads which – when repaired and expanded – will form a vital route to the border and beyond, with Baaj serving as a waypoint.
“We are not leaving Ba’aj,” said one senior PMF member. “This will be our main base in the area.”
That afternoon, semi-trailers carrying blast walls trundled through the town toward a government building in the centre.
Not far away, the Nujaba Movement, an Iraqi militia that led the fight against forces in Syria opposed to Bashar al-Assad, has set up a base. So too has every one of the militia protagonists to have fought Isis inside Iraq.
The transformation of Ba’aj, from an out-of-bounds haven for Isis leaders to a focal point for Iran’s efforts to change the regional dynamic, is taking place rapidly, even before hundreds of booby-trapped homes have been cleared.
“It’s important,” said the PMF member. “We will do a lot from here.”
In early May, PMF leaders told their senior members a land corridor that would give Iran a supply line across Iraq and Syria and into Lebanon, had been rerouted south of Mt Sinjar, 25 miles to the north. Ba’aj was to be the first main hub, and from there the road was to cross into Syria through the city of Deir Azzour and town of Mayedin, both of which remain under Isis control.
Since then, Iranian backed forces, led by Suleimani, have massed on both sides of the border near the Damascus-Baghdad highway, leading to at least three clashes with US forces and their Syrian opposition proxies near the town of Tanf.
The highway is a focal point of efforts to safeguard a viable route, but senior PMF members said other potential corridors were also being explored as the collapse of Isis rapidly changes the battlefield around the border. A path through Deir ez-Zor, Mayedin and Palmyra and then on toward Damascus is, for now, a preferred option, they said.
The movement of forces around the border area has become a bewildering game of chess between multiple players, with Iranian-backed militias leading the Syrian army toward Iraq from the west, and the same leadership moving Iraqi militias toward them from the east.
Earlier this week, the two forces met at a point on the map between Mayedin and Deir ez-Zour – a pivotal moment in the Syrian war and the three-year fight against Isis – and at least a partial fulfilment of Iran’s plans to secure an arc of influence.
The effect has also been to stymie US intentions to move north from Mayedin to fight Isis in its last redoubt, which is thought likely to be to the west of Deir Azzour.
With spheres of control now physically taking shape across the battlefield, Muhandis was bullish about what may come next, but reluctant to reveal whether PMF units will now openly cross into Syria.
“Isis now is in the Euphrates basin in Syria and Iraq, he said. “They are trying to stay there. We want to do a military operation there. I think it will take at least a year, maybe more.
“Al-Qaida was defeated, and then came back as Isis. If we didn’t destroy everything, all this area would be Isis again under a different name.”
To the south of Ba’aj, a wasteland of hurriedly-emptied towns and villages suggest that if Isis did return, it would not be anytime soon. “The fight is across the horizon,” the senior PMF member said. “Securing Syria will stabilise the region. We will see this through.”
Muhandis was more circumspect. “If a threat remains from Syria or another area, any country that respects itself should go to where the terrorists are in defence. If we need to make contact [between the Iraqi and Syrian governments] we can do it, but the order should come from the Iraqi government.”