As Iraqi officials prepare to draft the country's new constitution, fierce debate is expected over the status of Kirkuk, the center of northern Iraq's oil industry. Formerly known for its ethnic harmony, Saddam Hussein's policy of forced population shifts, called Arabization, has torn the fabric of the province. Now the Kurds want it back.

Ismael Yassin and his wife, Amira Mohammed, are building a simple, one-story house made of cinder blocks. About a year ago, the Kurdish couple and their eight children returned to their village of Turkolan, outside the city of Kirkuk.

Kirkuk Emerges as Faultline for Civil Conflict in Iraq

Like thousands of other Kurds, they were driven from their homes in 1987 in a sweep by the former Saddam Hussein regime. It was part of Saddam's policy of "Arabization," designed, in part, to move Kurds out of strategic areas like Kirkuk, and to shift the ethnic balance by bringing Arabs into the city, the northern headquarters of Iraq's oil industry.

Kirkuk Emerges as Faultline for Civil Conflict in Iraq

Mr. Yassin says his family returned, because Turkolan is their home. They wanted to come back as soon as Saddam Hussein was gone.

Kirkuk Emerges as Faultline for Civil Conflict in Iraq

The group, Human Rights Watch, estimates that more than a quarter-million Kurds and non-Arabs were forcefully expelled from their homes in Kirkuk.

Since 2003, tens-of-thousands of Arab settlers have left the region, but tens-of-thousands of others have chosen to stay in towns and villages they now think of as home.

Meanwhile, local officials estimate more than 100,000 Kurds have returned. Many of them are living in miserable conditions, in camps for the internally displaced, and in villages with little running water or power.

But that has not affected Amira Mohammed's satisfaction at having returned home.

Ms. Mohammed says she feels free in Turkolan, and does not think anyone would use force to move them out again.

But the combustible mix of ethnic resentment, poor living conditions and fear for the future in Kirkuk has led to violence.

Rights groups report that there have been attacks on leaders from all three predominant ethnic groups. They also report tit-for-tat killings across ethnic lines in communities across the province. Kirkuk has also suffered from insurgent attacks on oil and gas pipelines, plus car-bombings and other terrorist activity.

Officials say the violence has not flared out of control. But the situation is complicated by politics.

Kurds represent the second-largest voting block in the national assembly. Analysts expect fierce debate by lawmakers over whether to redraw the internal borders in Iraq to return Kirkuk to Kurdish control. A referendum may ultimately be held to determine Kirkuk's status.

Adnan Mufti, a senior member of the Patriotic Union of Kurdistan, says the debate is not about the oil.

"Historically, Kirkuk is part of Kurdistan, and the majority are Kurd - and they suffered too much," Mr. Mufti says. "Thousands-and-thousands of them have suffered and been killed during the dictatorship. So, it is very normal that we are looking for the right of Kirkuk people, and the right to return back to Kurdistan area. But the oil, it is no problem. Kurdistan is rich. All Iraq is rich. Oil is everywhere."

Even within the Kurdish region, internal politics have made settling the Kirkuk issue more difficult.

During the 1990s, the Kurdish Democratic Party and the Patriotic Union of Kurdistan were locked in a political rivalry that gave way to civil war. A peace deal was struck in 1998. But it was only within the past few days that the two sides hammered out the details to integrate the rival administrations that governed the region.

Mahmoud Othman is formerly with the Kurdish Democratic Party, and says, against the backdrop of national and local politics, ethnic tensions could be exacerbated. He calls Kirkuk a potential troublespot.

"One reason is, different nationalities, the Turkomans, the Arabs, the Kurds, the Assyrians, the Kurdians - this, by itself - it is not so easy to connect everybody together ? So I think problems are ahead. We have to try to face them and solve these problems through dialogue ? through trying to return the people who were ousted from the areas, finding a solution for the Arabs who were installed in their places," Mr.Othman says.

Ismael Yassin and his wife are lucky. They are affiliated with a political party, which gave them about $1,000 and cement to help them build their new home.

About a kilometer away, Samer Aziz is not as fortunate. A Kurd married to an Arab man, she and her family are squatting in a former military barracks that used to house guards for Kirkuk's oil refinery.