The colonel pulls his Mercedes into the parking lot of the drab, 11-story concrete building, scanning the scene for suspicious cars.
Before reaching for the door handle, he studies the people loitering nearby in hopes he will be able to recognize anyone still there later in the day. He grips his pistol, the trigger cocked, wary of an ambush.
He has arrived at his office.
This is Iraq's Ministry of Interior -- the balkanized command center for the nation's police and mirror of the deadly factions that have caused the government here to grind nearly to a halt.
The very language that Americans use to describe government -- ministries, departments, agencies -- belies the reality here of militias that kill under cover of police uniform and remain above the law. Until recently, one or two Interior Ministry police officers were assassinated each week while arriving or leaving the building, probably by fellow officers, senior police officials say.
That killing has been reduced, but Western diplomats still describe the Interior Ministry building as a "federation of oligarchs." Those who work in the building, like the colonel, liken departments to hostile countries. Survival depends on keeping abreast of shifting factional alliances and turf.
On the second floor is Gen. Mahdi Gharrawi, a former national police commander. Last year, U.S. and Iraqi troops found 1,400 prisoners, mostly Sunnis, at a base he controlled in east Baghdad. Many showed signs of torture. The interior minister blocked an arrest warrant against the general this year, senior Iraqi officials confirmed.
The third- and fifth-floor administrative departments are the domain of Prime Minister Nouri Maliki's Islamic Dawa Party, a Shiite group.
The sixth, home to border enforcement and the major crimes unit, belongs to the Badr Organization militia. Its leader, Deputy Minister Ahmed Khafaji, is lauded by some Western officials as an efficient administrator and suspected by others of running secret prisons.
The seventh floor is intelligence, where the Badr Organization and armed Kurdish groups struggle for control.
The ninth floor is shared by the department's inspector general and general counsel, religious Shiites. Their offices have been at the center of efforts to purge the department's remaining Sunni employees. The counsel's predecessor, a Sunni, was killed a year ago.
"They have some bad things on the ninth," says the colonel, a Sunni who, like other ministry officials, spoke on condition of anonymity to guard against retaliation.
The ministry's computer department is on the 10th floor. Two employees were arrested there in February on suspicion of smuggling in explosives, according to police and U.S. military officials. Some Iraqi and U.S. officials say the workers intended to store bombs there. Others say they were plotting to attack the U.S. advisors stationed directly above them on the top floor.
Months after the arrests, it's unclear whether the detainees are Sunni insurgents or followers of Muqtada Sadr, the anti-U.S. Shiite cleric whose portrait stares down from some office walls in a sign of his spreading influence in the ministry.
Partitions divide the building's hallways, and gunmen guard the offices of deputy ministers. Senior police officials march up and down stairs rather than risk an elevator. They walk the halls flanked by bodyguards, wary of armed colleagues.
"What is in their hearts? You do not know who they belong to," a senior officer said.
The factionalization of the ministry began quickly after Saddam Hussein's fall. As with most Iraqi government departments, deputy ministers were appointed to represent each of the country's main political parties. Deputies then distributed jobs among party stalwarts.
The initial winners were the Kurdish Democratic Party and the two Shiite parties, Dawa and the Supreme Islamic Iraqi Council, which sponsors the Badr Organization. The Kurdish party is one of two factions that control Iraq's northern provinces.
Sadr's Al Mahdi militia started late in the patronage game but has made significant inroads, particularly among the guard force that surrounds the ministry compound.
Parties representing the Sunni minority, which controlled Iraq in Hussein's day, have been almost entirely purged from the ministry in the last two years. Three of the ministry's longest-serving Sunni generals have been killed in the last year.
Interior Minister Jawad Bolani, a Shiite leader who took office last summer, has attempted to repair the ministry's reputation. He has removed the leaders of eight of nine national police brigades and 17 of 27 police battalions, which have been accused of killings and mass kidnappings. But change has come slowly.
"There is a lot of pressure, there is influence from everywhere, from everyone: political parties, religious groups, the government itself, from familial and tribal influences," said U.S. Army Brig. Gen. Dana Pittard, who supervised the U.S. advisors to the national police until last month.
"It would be very difficult for anybody to operate as a leader in this environment, and the Iraqis do," Pittard said.
No floor has posed more of a challenge than the seventh, which houses the intelligence division. In theory, the intelligence office should be key to tracking and combating the insurgents who bomb Iraq's streets and marketplaces and attack U.S. soldiers. Instead, the division has been hobbled by a power struggle between two of America's nominal allies in Iraq, the Kurds and the Supreme Islamic Iraqi Council.
The fight came to a head earlier this year with a death threat against the Kurdish deputy minister in charge of intelligence, Hussein Ali Kamal. The Kurdish leader, who controls the eastern wing of the floor, was battling for control of the intelligence apparatus with his deputy, a Badr militia commander who dominates the western side.
Several months ago, U.S. advisors warned Kamal that his life was in danger, most probably from the Badr militia, and advised him to stay in the Green Zone, away from the ministry building in east Baghdad. He stayed out of the ministry for several weeks.
The Shiite deputy, Basheer Wandi, better known as Engineer Ahmed, was appointed in the spring of 2005. Around the same time, Shiite militias began aggressive efforts to target and kill Sunnis in Baghdad, often using police cover to detain Sunnis in secret prisons and carry out assassinations.
They made little effort to hide their methods. A U.S. police advisor recalled a visit to the seventh floor in the summer of 2005, a few months after Engineer Ahmed took office.
"When we left Hussein Ali Kamal's office in the eastern wing of the ministry building, we walked down to the other end to see someone else. As we walked down, there was an Iraqi prisoner on the floor, in handcuffs, hands tied behind him, the floor was just soaked in clear fluid, he was still vomiting and gagging. It looked like he had vomited gallons," the advisor recalled.
One of Engineer Ahmed's work sites was a secret prison set up in a bunker in Baghdad's Jadriya neighborhood, U.S. officials said. In November 2005, U.S. troops uncovered the prison, finding 169 detainees, many showing signs of torture.
After the bunker was found, U.S. officials documented Engineer Ahmed's role. "There were case files written and prepared, presented to Maliki by the Americans that laid out responsibility," said a Western diplomat who spoke on condition of anonymity because of the sensitivity of the subject.
Top American officials eventually decided to back off the effort to hold Engineer Ahmed accountable because of the political problems involved, two Western diplomats said.
Engineer Ahmed enjoyed almost untouchable status in the Badr militia for his reputation as a fighter against Hussein.
"Someone like that is a real war hero for the Shiites. It's very hard for Maliki to allow any action to be taken against them. From our side, it becomes how much political capital do we possess in doing something Maliki is going to find very, very difficult to do," the Western diplomat said.
After the threat on Kamal's life, Engineer Ahmed was transferred. But U.S. and other Western officials, some of whom suspect Maliki's government of playing a shell game to protect militant leaders, say he is now working out of Maliki's security bureau. Shiite officials insisted that Engineer Ahmed was innocent.
U.S. military documents viewed by The Times show that Engineer Ahmed has had frequent contact with the prime minister. He even played a role in drawing up the current U.S.-Iraqi security plan for Baghdad.
Kamal, the Kurdish deputy minister, says he believes the ministry has started reining in Shiite militias but knows suspect figures still operate openly in the ministry, including Gen. Gharrawi on the second floor.
Fifty-seven warrants were issued in November after inspectors discovered evidence of torture at the police base Gharrawi controlled, but only two men have been arrested.
Interior Minister Bolani set up a committee to review the case but blocked the arrest warrant against the general after American officials failed to bring forward the accusing witnesses, Kamal said. "Now [Gharrawi] thinks he is an innocent man. We couldn't bring people to face him," Kamal said.
Western officials see Gharrawi's case as an indicator of whether the Iraqi government is willing to hold senior Shiites accountable for criminal behavior by their forces.
"He's senior enough that the question arises, if he went down, then what's the next step? The next step is for other senior generals or indeed ministers to go down as well," the Western diplomat said.
Even the remaining Sunni members of the police force respect Bolani for trying to rein in the ministry. But they know he depends on a web of fragile political alliances and wonder whether any political figure can undo the effects of several years of recruiting hard-line militia members to the ministry.
"Even if they brought the prophet Muhammad or Jesus, they couldn't control them," said a senior ministry official. "They have an agenda. They follow their parties."