By Michael Georgy

JULUKHAN, Iraq (Reuters) - Major General Najm al-Jubbouri, a top commander in the offensive against Islamic State in the Iraqi city of Mosul, peered through binoculars at flames after his men shot dead an Islamic State suicide bomber.

It was a small victory for a man whose war against jihadists is deeply personal.

“You are heroes,” he said through a walkie talkie as Iraqi forces cleared another village, hoping to open a new route to the militants’ stronghold of Mosul. “You are heroes”.

Last year, Iraqi Prime Minister Haider al-Abadi asked Jubbouri to return home from the United States to help lead the fight against Islamic State, which swept through Mosul and other parts of northern Iraq in 2014 and imposed a reign of terror.

Jubbouri is upbeat as he paces on the rooftop of a house that serves as a makeshift command center, surveying the battlefield and tightly managing advances.

But he is acutely aware of what Islamic State, also known as ISIS, is capable of.

Last year, he watched an Islamic State video broadcast on social media which showed the drowning of prisoners who are locked inside a steel cage and slowly lowered to their deaths in a pool.

Some of the victims were Jubbouri’s cousins, he said.

“My relatives and citizens suffered a lot from al Qaeda and ISIS. I decided to return back here. In Mosul, ISIS killed a lot from my tribe and from my friends,” he told Reuters in an interview.

Jubbouri left his family behind and his job at the National Defence University in the United States and put on his military fatigues again at home.

Eager to avenge the deaths of his relatives and help stabilize Iraq, Jubbouri is trying to figure out ways to overcome the complex challenges of fighting Islamic State in Mosul, home to about one million people.

Iraqi forces can’t move heavy weapons and tanks through Mosul’s narrow streets, and Islamic State is using civilians as human shields to slow government advances, said Jubbouri, who served in Saddam Hussein’s army for decades.

In the desert just beyond Jubbouri are two army trucks mounted with machineguns, primed to attack any suicide bombers in vehicles who try to approach the makeshift command center, which is surrounded by bodyguards.

“We want to remove the cancer (of Islamic State) from the body and this is a very difficult mission inside Mosul,” said Jubbouri.

Jubbouri, who moved to the United States in 2008, is acutely aware of the dangers posed by Islamic militants, and the sectarian animosities which have destabilized Iraq.

As mayor of Tel Afar from 2005-2008, he cleared out al-Qaeda fighters from the town and promoted reconciliation between Sunnis and Shi’ites.

Iraq has been struggling to find a formula for stability since a U.S.-led invasion toppled Saddam Hussein in 2003.

Even if Islamic State is defeated in Mosul, Iraqi leaders must ensure that the same ethnic and sectarian hostilities which helped Islamic State establish a widespread presence in the country do not creep up again.

The group initially won over Sunni supporters because that sect felt marginalized by the Shi'ite-led government in Baghdad.

Jubbouri called for an end to a governing system which allocates top posts based on sects.

“It won’t be rosy. Many difficulties,” he said. “Some politicians will not like to change because many of them would lose their positions.”

For now, he is focused on the fight against Islamic State. Jubbouri said Iraqi forces had set a six-month timetable for the Mosul campaign. But he is confident of victory by the end of this year, predicting the group will collapse.

So far, Iraqi forces have captured about 60 percent of eastern Mosul, and the western part of Iraq's second biggest city could prove far more dangerous.

“In beginning, everyday we faced between 60 and 70 car bombs. Now we are facing about two or three,” said Jubbouri, as his forces fired mortar bombs and rockets at an asphalt factory where militants strapped with explosives were positioned.

(Editing by Simon Cameron-Moore)