Naturally, Sunni Arab terrorists get no such breaks from the cops. This is why the Sunni terrorists tend to use suicide bombers. One guy, one car, one bomb. The Sunni Arab terrorist groups have this drill down cold, and only have to pull off a few of these a week to infuriate the Shia Arabs, and trigger more reprisal killings. The way the Sunni Arab terrorists see it, this will eventually bring salvation and rescue from the rest of the Sunni Arab world. Such salvation is not forthcoming, and other Sunni Arab nations have made this clear. Undismayed, Iraqi Sunni Arabs now believe that there will be popular uprisings in other Sunni Arab countries, that will force those governments to invade Iraq and rescue the beleaguered Sunni Arabs.
Meanwhile, most Iraqi Shia (who comprise about 60 percent of the population), are unable to get too upset at the dozens of Iraq Sunni Arabs who are murdered by death squads each week. It's difficult for Westerners to appreciate the degree of hatred the Iraqi Sunni Arabs earned over the last few decades, and especially during the last ten years of Saddam's rule. But this is not what most Iraqis worry about. No, the big problem is simply driving the common criminals off the streets. The Shia death squads, and Sunni Arab terrorists, are just components of the lawlessness that tormented Iraq even before Saddam was overthrown. In his last years, Saddam was using government sponsored thugs, and plain-old-criminals, to persecute real, or potential, rebels. Now, all these thugs are either out to simply steal and extort, or to settle old scores (the terrorists and death squads.)
The six week effort to bring down the mayhem rate in Baghdad did make it clear that, more people and better communications would make a difference. Cleaning the Shia fanatics out of the police force would help as well. Right now, Sunni Arabs simply don't trust the cops. There have been proposals to bring Kurdish police battalions down from the north. While Kurds hate Sunni Arabs as well, the Kurds are also Sunni, and have not been as murderous as the Shia extremists have been. The Sunni Arab communities say they would accept Kurdish police, and the Shia have no objection either. However, the Kurdish cops have to accept the fact that they might find themselves battling Shia death squads, in addition to Sunni Arab terrorists.
Baghdad is also a particularly difficult place to police. Many of its six million residents live in low rise slums. Those in east Baghdad contain most of the Shia Arabs, and are guarded (if not well protected) by some Shia militias. But the Sunni Arab areas, during Saddam's time, were well patrolled by police and special security units. That protection is gone, and even the wealthy Sunni Arab neighborhoods, that have hired lots of private guards, are getting a taste of Shia revenge.
There may be another attempt to lock down Baghdad before the end of the year, and definitely another next year. It's a goal everyone wants, but one the government has not been able to muster the resources to pull off.
In mid-June, the Iraqi government sent 75,000 soldiers and police into Baghdad, with the idea of imposing a degree of law and order that the city had not seen for some time. It didn't work. The reasons were many. One of the key problems was the lack of administrative efficiency within the Iraqi security forces. Put simply, the right hand often doesn't know what the left hand is doing. The Iraqis are not terribly upset with this. That's because Iraq has never operated according to Western standards of efficiency. This means that police and army units don't coordinate very well. This is a particular problem, because the Ministry of the Interior has become a safe place for Shia death squads to operate from. If not that, then many Shia police (and most of the police are Shia) will give a wink and a nod to any carloads of angry looking Shia gunmen that pass by.