By Leila Fadel - Washington Post Foreign Service

BAGHDAD - Iraqs parliament achieved an important milestone Thursday agreeing on who would hold the countrys top leadership spots after more than eight months of acrimonious negotiations. But a dramatic walkout by members of the Sunni-backed Iraqiya bloc marred the nearly five-hour session and underscored the deep divisions and distrust that dominate the countrys political system.
The days events which appeared to catch U.S. officials off guard followed a deal late Wednesday on a power-sharing arrangement among Iraqs biggest political factions and they were a vivid illustration of both the dysfunction that remains here and the small glimmers of hope about the future.
Iraqiyas move also raised the prospect that some Sunni Arabs disaffected by the political process could take up arms again just as the United States moves toward a planned withdrawal of forces by the end of 2011.
U.S. hopes for leaving behind a stable Iraq rest heavily on the establishment of a fully representative government that all of the countrys major factions can support. But Thursdays chaotic session reflects how challenging that will be.
Despite the twists and turns lawmakers reappointed President Jalal Talabani a Kurd who renamed incumbent Nouri al-Maliki a Shiite as prime minister. In addition a member of Iraqiya was elected speaker of parliament. With the three top slots resolved Maliki will now begin to distribute ministries and other top jobs a process that has the potential to be as divisive as the initial phase of government formation.
The moment of high drama came when members of the Iraqiya bloc - which by a slim margin won more seats in Iraqs 325-member parliament than any other bloc - walked out of the session to protest what they called duplicitous tactics by political rivals and broken promises to roll back a controversial law that they feel unfairly targeted their members.
They have to know that they cannot run the parliament the way they want said Falah al Naqib a legislator from Iraqiya. He called the walkout a strong and important message of Iraqiyas power. There is no trust. The political process is very fragile. You can see that there are major differences. They should at least respect their promises.
In Washington administration officials professed calm in the midst of the Iraqi storm which they described as an unsurprising upheaval that would soon be smoothed rather than a cause for concern that the deal was collapsing. The more important take-away from the day officials said was the election of an Iraqiya speaker and Kurdish president according to plan. U.S. officials had been pushing a power-sharing arrangement as a way to break Malikis monopoly on power.
The walkout dealt a setback to what was an eagerly awaited turning point in the impasse that has paralyzed Iraqi politics since the inconclusive March 7 election. After the departure of Iraqiya the remaining lawmakers voted to elect Talabani to the presidency. Some observers feared the decision to proceed in the face of Iraqiyas departure could eventually ignite a national crisis.
But Jaber al-Jaberi a top Iraqiya official said the bloc would probably consider returning to parliament if a compromise solution were reached and Iraqiya received assurances that the other groups in the new government will make good on their promises.
Thursdays session had been expected to go smoothly after all major blocs agreed late Wednesday to participate following promises about how positions in the new government would be distributed. But the precarious nature of that pact quickly became apparent.
After Osama al-Nujaifi of Iraqiya was elected speaker of parliament along with two deputies from the Shiite Sadrist bloc and the Kurdish alliance Nujaifi asked that details of the government formation deal be ratified through a vote. These included lifting a ban that precludes three Iraqiya members from participating in the government for alleged allegiance to Saddam Husseins outlawed Baath Party.
The Justice and Accountability Commission a body run by rival Shiite politicians banned many members of Iraqiya from running for parliament for the same reason.
After lawmakers voted not to tackle the issue an argument broke out and Iraqiya members stormed out of the session skipping out on the vote to appoint the president. Nujafi was the only Iraqiya member who remained.
You are from us Iraqiya put you there said Iraqiya lawmaker Mohammed al Timmimi before he left.
I am the parliament speaker I am not from Iraqiya Nujaifi responded.
Nujaifi later walked out as well saying there was no trust. But he subsequently returned and voted for the president in a second round.
This is not a crisis said Sami al-Askari a member of Malikis political bloc. Were continuing because we have a quorum. I dont know what Iraqiyas plan is but Im sure theyll be part of the government and the process.
The walkout occurred in the midst of a White House briefing called to tout the agreement as a victory and as a big step for Iraq.
This is a government that is made in Iraq said one of two senior administration officials who spoke to reporters on the condition of anonymity. It is not the result of influence or work of any outside actor any outside country.
The officials credited Massoud Barzani the president of the semiautonomous Kurdish region with organizing the negotiations that led to the breakthrough. They acknowledged high-level calls from Washington including calls from President Obama over the past week in which he appealed to the Kurds to relinquish the presidency to Iraqiya.
Asked about disappointment expressed by some Iraqiya members over Malikis retention as prime minister and concerns that some Sunnis feeling marginalized would resume violence one of the officials said that Iraqiya was all in with respect to the new government and that in the weeks ahead the positions they will hold in government. . .will vindicate their decision to participate.
After the briefing when word of the walkout reached the White House an official urged patience saying Lets wait and see what happens.
An American diplomat called the walkout a hiccup and said this will work itself out. Its still fragile the entire thing is still fragile there is no question.
On Thursday night some celebrated in Iraqs streets. But others expressed a sense of resentment especially those that had voted for secular Shiite Ayad Allawis political bloc. After more than eight months of waiting for a government they voted for they are instead getting leaders who bartered their votes for positions and a slew of the same faces that governed in the past several Iraqis said.
They manipulated us and were back to square one. A government of sectarian quotas where is democracy? Hamid al Ameri a 51-year-old retired military officer in Baghdad said. Its a joke; they are laughing at us. Its a puppet show.
Staff writer Karen DeYoung in Washington and special correspondent Aziz Alwan in Baghdad contributed to this report.