BAGHDAD -- The American ambassador to Iraq, Zalmay Khalilzad, was rushing to his residence from a visit to a new electrical plant in Baghdad, a landmark at a time when Iraqis get only a few hours of electricity a day. Next he was taking U.S. House Speaker Dennis Hastert to meet Iraq's new prime minister, Nouri al-Maliki. Then on to confer with Gen. George W. Casey, head of U.S. forces in Iraq, about a new security plan that Mr. al-Maliki is developing to try to halt the anarchy overtaking Baghdad.
Mr. Khalilzad, an Afghan American of endless charm and energy, is in constant motion, even as his key role in Iraq is about to undergo a substantial change. For months, he acted as the essential facilitator in the effort to form a national unity government, consulting with leaders of every ethnic and religious faction over tea in the Middle Eastern fashion of his youth.
"I was the attorney for the Sunnis," he says, referring to his role in bringing disaffected Iraqi Sunnis into the political arena. This led Shiite political leaders to accuse Mr. Khalilzad - a Sunni Muslim - of siding against them.
Five months after elections, a national unity government has finally been formed that includes Sunnis. Now, says Mr. Khalilzad, his new role is "to help the government" succeed.
Many Iraqis ask whether this long-awaited government will make any difference. In an interview at his residence, adorned with oriental rugs and paintings by Iraqi Americans, Mr. Khalilzad was frank about the hurdles ahead.
On the positive side are the character traits displayed by Mr. al-Maliki since taking office. "He is a good chief executive," Mr. Khalilzad says. "You ask a question, and he looks at the options and makes decisions. He sets priorities." This is a huge improvement over Mr. al-Maliki's predecessor, Ibrahim al-Jaafari, who had trouble making decisions and tended to ramble in meetings and interviews.
A second positive is the presence of Sunnis in the government. "Their participation is a strategic change," says the ambassador. But Sunni participation is not enough.
Sectarian violence has increased since the bombing of an important Shiite shrine in February by Sunni extremists led by Abu Musab al-Zarqawi; he just called again on his followers to kill Shiites. The bombing provoked Shiite militias to seek revenge, which frightens Sunnis into looking to their militants for protection. Down this road lies civil war.
"In the next three to six months," Mr. Khalilzad says, "the Iraqi people will judge the impact of this government on sectarian violence and reconciliation. The new prime minister understands this. The question is the doing."
Mr. Khalilzad suggests initial steps Mr. al-Maliki could take: a ban on carrying unauthorized weapons on the street, to be enforced by Iraqi and coalition troops, and efforts to prevent Iraqi security forces from cooperating with sectarian militias.
Improving security in Baghdad is also crucial. Such steps require the "appointment of strong ministers who are perceived as capable and nonsectarian," Mr. Khalilzad says. But the two key ministries of interior and defense remained unfilled because of sectarian squabbles.
I asked Mr. Khalilzad whether the Sunni leaders in the government have the clout to undercut the Sunni-led insurgency, which might, in turn, ease the way toward demobilizing Shiite militias.
His reply: "The Sunnis in government are not in command and control of the insurgency, but they have credibility in their communities and can facilitate reconciliation." To strengthen the hand of these Sunnis, Mr. Khalilzad says the United States is willing to talk about a "condition-based road map" for U.S. troop pullbacks. This would not set out a timetable but would give benchmarks for withdrawal as violence decreased and Iraqi capacity improved.
In turn, says Mr. Khalilzad, "there has to be pressure on Sunnis to deliver on the insurgency. They can't have one foot in the government and another in the insurgency, just as Shia can't have one foot in the government and another in the militias."
To change that dynamic, Mr. al-Maliki, a member of the Dawa, a Shiite Islamist party, would have to rise above the sectarian politics of which he is a part. He would have to embrace a politics of unity that is "not just words, but substance," says Mr. Khalilzad.
"You have a very skeptical population [in Iraq] that wants to see results," says Mr. Khalilzad. The ambassador's new mission will be to help Mr. al-Maliki produce.
Trudy Rubin is a columnist for The Philadelphia Inquirer. Her column appears Tuesdays and Fridays in The Sun. Her e-mail is firstname.lastname@example.org.