Just as the courts are thrashing out the legal status and rights of prisoners held at Guantanamo Bay, the courts will wrestle with the responsibility and liability of private companies on the battlefield. "Other countries develop rules and regulation," Singer said. "We do reform through litigation, not legislation."
There are about 20,000 private military contractors in Iraq performing tasks that the military once did. They guard diplomats, drive fuel trucks, maintain sophisticated weapon systems and interrogate prisoners. More than 200 contractors have been killed in Iraq, and hundreds more have been wounded.
"When the Pentagon employs a far greater percentage of contractors than in any previous action, it raised the question of accountability," said Scott Silliman, a retired Air Force legal officer who heads the Duke University Law School's Center on Law, Ethics and National Security. "We have never had to deal with it before; you've never had such wholesale contracting out."
The four Blackwater contractors -- Wesley Batalona, Scott Helvenston, Michael Teague and Jerry Zovko -- were killed performing a job that in previous wars was done by the military: escorting a convoy through hostile territory.
As private citizens carrying out military activities, contractors don't fit neatly in the well-defined worlds of military or civilian law.
"The industry falls through the cracks at the national and international level," Singer said. "Private military contractors exist in the same legal vacuum as detainees at Guantanamo Bay."
Working in legal limbo
If there is any doubt that private contractors work in a legal limbo, compare the experiences of the military and the contractors when it comes to criminal charges.
The military justice system has investigated and prosecuted hundreds of soldiers in Iraq, from alcohol-related charges to murder to the torture of inmates at the Abu Ghraib prison.
But Singer and others say they can't find a single criminal charge filed against any of the 20,000 contractors working in Iraq over the past two years, even the six civilian contractors implicated in abuse at Abu Ghraib.
The head of a trade group representing private security companies said his industry wants to be held to the highest standards of conduct.
"Whether you're wearing camouflage or blue jeans, you need to be held accountable," said Doug Brooks, president of the International Peace Operations Association, a trade group that represents companies (including Blackwater) that sell services to the government.
This makes good business sense, he said, because potential clients are much more likely to hire firms with records of proper behavior.
Brooks declined to comment on the Blackwater lawsuit, which, as a civil case, does not involve criminal charges.
Suit faces hurdles
At its heart, the lawsuit is a dispute over a contract, so it's not surprising the dispute has ended up in court.
Legal experts point out a number of obstacles to the families' winning in court.
For starters, the four contractors, all military veterans, knew the risks of working in a war zone.
And if they didn't, the contracts they signed spelled out the dangers in graphic detail: "being shot, permanently maimed and/or killed by a firearm or munitions, falling aircraft or helicopters, sniper fire, land mine, artillery fire, rocket-propelled grenade, truck or car bomb, earthquake or other natural disaster, poisoning, civil uprising, terrorist activity, hand-to-hand combat, disease, poisoning, etc., killed or maimed while a passenger in a helicopter or fixedwing aircraft, suffering hearing loss, eye injury or loss; inhalation or contact with biological or chemical contaminants (whether airborne or not) and or flying debris, etc."
Blackwater is likely to argue that the four men willingly signed on, fully aware of the dangers, and were compensated for the risk with hefty pay of $600 a day.
"This is not a contract where you had no options," said George Christie, a Duke law professor and specialist on lawsuits for damages. "When Blackwater says take it or leave it, there are other ways of earning a living."
The contracts throw up other barriers. The workers signed a release giving up most of their rights to sue Blackwater if something bad happened to them. Their families and their estates can't sue, either.
Christie pointed out that, under the terms of the contracts signed by the four Blackwater workers, the families can't sue the company even if the deaths were entirely the result of Blackwater's negligence or gross negligence.
To prevail, Christie said, it will be necessary for the families to meet a higher legal standard: They will need to show that Blackwater was reckless.
A judge and jury would have to draw the line between murky worlds of "negligence" and "recklessness."
It's not a clear-cut line, said Christie, who cited the conventional wisdom about the difference between negligence, gross negligence and recklessness: "It's the difference between a fool, a damned fool, and a goddamned fool," he said.
Regardless of whether the families recover any money from Blackwater, the lawsuit is not likely to help the company, which must rely on its reputation to compete for new work.
"These companies don't like to see their names in the media, especially when they are accused of not supporting their personnel properly," said Singer, the Brookings Institution expert.
Likewise, Singer said, active-duty Special Forces soldiers have told him they use the Fallujah ambush to persuade their fellow soldiers not to leave the military for the higher pay of private military contracting.
Duke's Silliman said he expects Blackwater to fight the lawsuit vigorously and not reach a settlement with the families.
"If I were counsel to Blackwater, knowing the nature of these contracts, I would press on," he said. "If you settle, you're opening the Pandora's box and will open up Blackwater and every other contractor to similar actions in the future."
Blackwater has declined to discuss the lawsuit. Chris Bertelli, a company spokesman, said that a key issue in the case will be the Defense Base Act, which established workers' compensation insurance for employees of overseas government contractors. The dependents of Batalona, Helvenston and Teague (Zofko left no dependents) have begun receiving lifetime payments of $1,100 per week tax-free, Bertelli said. Blackwater will argue that these payments are the only remedy available to the families by law.
Dan Callahan, a California-based attorney for the four families, said he thinks the law doesn't apply in this case, because the four men weren't direct employees of Blackwater, but instead were hired as contractors.
Because the suit is the first of its kind, Callahan said, it will help bring accountability to a fast-growing industry that has little.
"The military has a chain of command and courts-martial, but there's no chain of command, no courts-martial for these thousands of contractors in Iraq."