Al-Mazraa, Iraq (CNN) Al-Mazraa is a dusty village just south of Baiji, where a battle is raging between ISIS fighters and pro-government Iraqi forces trying to push them out.

Under normal circumstances it's a sleepy farming town just off the Saddam Hussein-era highway linking Baghdad and Mosul.

Today it's a staging point for pro-government forces heading into nearby Baiji.

Battered, bullet-pocked Humvees and armored pick-up trucks rumble through the trash-strewn main street, while young soldiers and militiamen mill around in the shade seeking relief from the brutal mid-day heat.

A few residents mix with the fighters, including little boys curious about all the newcomers.

A month ago Al-Mazraa, a village of Sunni Arabs, was in the hands of ISIS, but according to resident Ammer Hashd Jraish, their hands were light.

"They would drive through here, but never stopped here," he says. Today Jraish, a man in his late forties with the ubiquitous dark moustache and sporting combat fatigues, is a member of the town council.

He's a member of the Hashd Al-Shaabi, the Popular Mobilization Units (PMU), a Shia-led paramilitary force partially armed, trained and advised by Iran. Although a Sunni, he -- like many others in Al-Mazraa -- has taken up arms with the Shia-led PMU. Jraish insists he had nothing to do with ISIS during the year they controlled the area.

I met him in the PMU's command center in Al-Mazraa, a sitting room in a villa full of chairs with maps on the walls and a big computer screen featuring another map of Baiji and the adjacent refinery.

Sitting next to the screen is a man perhaps in his sixties with a trim white beard and white hair. It's Abu Mahdi Al-Muhandis, PMU's commander and arguably the most powerful military leader in Iraq.

Abu Mahdi Al-Muhandis explains to Ben Wedeman the gains the PMU has made and their plans to defeat ISIS.

In this war where ironies abound, Al-Muhandis is on the U.S. government's list of designated terrorists for his involvement in the Iraqi insurgency, and for involvement in terrorist acts in Kuwait in the 1980s. But today he, like the United States, is fighting ISIS.

CNN producer Hamdi Alkhshali and I introduce ourselves to Al-Muhandis, who initially declines our request for a quick on-camera interview. After a little coaxing, however, he begins to explain the situation in Baiji on one of the maps on the wall, quickly conceding that despite what we were told by Iraqi officials in Baghdad, pro-government forces only control about 50% of the town and still have a way to go before retaking the refinery, Iraq's largest.

He is hesitant to be drawn on the United States and its role in the war on ISIS, brushing off questions with "it does not concern me" or "these are agreements between the Iraqi government and the United States."

After much pressing, he expresses scorn. "It's clear," he says: "The international coalition isn't serious in its operations. That's why Ramadi fell."

Abu Mahdi Al-Muhandis -- commander of Hashd Al-Shaabi (PMU) -- takes a call on his satellite phone.

Others in the room, including the commander of Iraqi Army operations in Baiji, Major General Jumaa Anad, nod in agreement.

Al-Muhandis points to the map, to a bridge over the Tigris River north of Baiji. "This bridge is on the main ISIS supply line between Baiji and Mosul. Every day for months now, fighters, equipment and ammunition move over this bridge. But until now the international coalition hasn't hit it."

Major General Anad, a 37-year veteran of the Iraqi Army, expresses the consternation one hears from many in Iraq these days, noting that it took the U.S. and its allies only 22 days to utterly defeat Saddam Hussein's regime in 2003.

"When the United States wants to do something, it does it," he tells me. "We fought them twice, in 1991 and 2003. They have incredible capabilities. If they were serious, they could crush ISIS."

When I ask him his reaction to the news that the Obama administration will send more than 400 additional troops to train the Iraqi Army , supplementing the around 3,100 already here, he scoffs.

"We don't need training, we need weapons. To detect land mines we are using sticks, just like in World War One. The Americans have the latest technology for land mines. That's the kind of help we need."

Ben Wedeman interviews Major General Jumaa Anad, commander of Salaheddin operations.

We didn't get a very close look at the fighting in Baiji. Mid-afternoon we ended up on the rooftop of a house commandeered by Sunni PMU fighters about 2.5 kilometers east of the town center.

The house was littered with half-eaten meals of rice and meat, hundreds of empty water bottles, clothing strewn all over the place. In one of the rooms a young man applies a bandage to his leg.

Explaining the lay of the land before us, local Sunni commander Khalil Awa says, "until now there are skirmishes with the remnants of ISIS, while others are fleeing toward Mosul."

Others on the rooftop tell us the ISIS fighters, whom they listen in to on their walkie-talkies, are a mixture of Chechnyans, Central Asians and Iraqis from Mosul.

From the rooftop we could hear small arms fire coming from Baiji, and an occasional thud, but could make out little else, everything is second-hand.

The haze is too thick.