There's probably little legal clout to the Iraqi government's vow Monday to expel the security firm that protects American diplomats. But that should not diminish the importance of the incident the day before, in which eight Iraqi civilians were allegedly killed by diplomatic guards, or the ongoing controversy about the conduct of the U.S. Embassy's security force. In addition to the personal tragedy for those cut down while passing through a busy Baghdad square, this was a setback for the very interests American diplomats are trying to promote, and it is largely of America's own making.

That's because the dispute isn't really about whether the gunners for Blackwater USA were at fault for the deaths that occurred when a convoy of SUVs reportedly returned fire from unidentified gunmen in Nusoor Square. First accounts are often wrong and the full story may never be told. The question is whether anything would happen to the guards even if they did kill innocent people. Through multiple decrees by past American administrators in Iraq, later imposed on the Iraqi government, contractors are largely immune from prosecution for the force they use here against Iraqis. There are some 20,000 to 30,000 private security contractors here now, presumably about the same as their presence over the past three years, and none has been prosecuted for the use of excessive force against local residents.

Iraqis know this and point it out constantly with stories of deaths involving contractors. A notorious one in the Green Zone was the allegedly unprovoked killing of a guard for an Iraqi vice president by a Blackwater employee on Christmas Eve. (U.S. officials acknowledged a killing occurred and promised to investigate.) Iraqi politicians cry out for changes in the Iraqi law to end what they see as the impunity of the contractors and note the contradiction it poses amid American efforts to promote the rule of law by the Iraqi government. U.S. soldiers who commit crimes here can be punished and have been jailed under military codes, but those don't apply to contractors. They often just get a flight out of the country when they get in trouble.

.Sattar's funeral (AFP/Getty Images)..

How much of a setback, then, is the murder? Abdul Sattar was the dashing, robed thirtysomething figure America could use as an example of what Sunnis can get if they turn against terrorists. His tribesmen were formed into security forces and paid salaries. He grew in stature to the point that he was allowed to meet George W. Bush when the president made his Labor Day visit to Anbar. The sheik died Thursday when, a U.S. military official told NEWSWEEK, a car parked near the entrance to the sheik’s large compound exploded as he passed by. His death could throw the movement into disarray.

That’s the story line, anyway. But nothing in Iraq, especially tribal politics, is that simple. Abdul Sattar was the leader of only one of several factions lining up with the U.S. military, and his influence was always questionable. He was a useful role model, but the other tribal leaders had made their own decisions to oppose Al Qaeda and its violent atrocities. They and their constituent tribe members saw two foreign forces on their turf, the United States and Al Qaeda. When Al Qaeda became too ruthless in its killings of tribe members who failed to support them and too brutal in its enforcement of fundamentalist Islam, the tribes sought the help of the other big force, the Americans. Abdul Sattar was one of the first to emerge and won the biggest public accolades. But Abdul Sattar, who even allies suspected of being a smuggler and opportunist in the great tradition of desert tribesmen, was hardly standing alone.

Abdul Sattar’s death could lead to jockeying and bloodshed among the tribes--but that might have happened anyway. It’s even plausible that he was killed with the help of competitors within his own movement. The death just highlights the tensions and dangers that already existed for a tribal alliance rife with divisions and shifting coalitions, based on a mixture of power, security and money.