Not long before the United States launched its invasion of Iraq, President Bush told the American people: "If war is forced upon us, we will fight in a just cause and by just means - sparing, in every way we can, the innocent."
He meant civilians: men, women, and children who had lived for a quarter-century under Saddam Hussein's iron-fisted rule - who were not part of Iraq's military forces, yet could not escape the horrors of war.
How well has Mr. Bush's pledge been kept? How many civilian casualties - "collateral damage," to use the antiseptic phrase - have resulted from the war, and the subsequent occupation in which people are killed and wounded nearly every day?
It's an impossible question to answer with sure accuracy. The nature of war - in particular this kind of war in this kind of place - makes it hard to tally the "innocent" victims. The Pentagon says it "monitors" civilian casualties but doesn't keep such figures. Human rights groups try, but they acknowledge that their figures are estimates at best.
Those estimates, however, signal that losses have been severe. Between 8,789 and 10,638 civilians have died since war began March 19, 2003, according to one group of British and American researchers that surveys media reports and eyewitness accounts.
It's also difficult to assign responsibility or blame. Many thousands of Iraqi civilians died during Hussein's reign, and 692 US-led coalition soldiers have died ending that regime. In war - by definition, the failure to resolve disputes without suffering - how do these losses figure into any kind of cost-benefit calculus?
Yet it's important to gauge the toll on civilians, say experts on the laws governing war and occupation. And current efforts to quantify civilian casualties come at a time when those laws are being tested as never before.
Battlefields may be hellish, yet they are regulated by a code called the Law of Armed Conflict.
This includes the Hague and Geneva Conventions (international protocols spelling out the rules of war, in place since 1907 and 1949, respectively), in addition to various international agreements supplementing them. In sum, its principles are military necessity, distinction, and proportionality, which add up to targeting only military objectives while avoiding noncombatants.
"These are all pretty gauzy standards involving vague terms, not given to easy quantification or decision in courtrooms," says Gary Solis, a retired Marine officer who has taught laws of war at the United States Military Academy at West Point.
"But the point is that there are standards, and we're ever more likely to see attempts to apply them in international forums," says Mr. Solis, now at the Georgetown University Law School in Washington. "And that's got to be a good thing."
Even though "major combat operations" have been declared officially ended, the US-run Coalition Provisional Authority - the occupier of Iraq - remains responsible for public order and safety there. At the same time, the resistance movements fighting the occupation are supposed to be bound by the Law of Armed Conflict as well - which means that attacks on civilian targets such as the new Iraqi police forces violate the rules of war.
At various times during the war and occupation, US officials have issued statements declaring that "even one innocent person injured or killed is something we sincerely regret."
It's difficult (and sometimes impossible) to distinguish civilian casualties from the victims of anticoalition guerrilla forces or criminals. Not all casualties are taken to hospitals where records are kept, and Muslim practice is to bury victims the same day they die, which makes recordkeeping even more challenging.
Though coalition forces in Iraq do not publish totals of civilian casualties (nor does international law require them to), they do make payments - usually several thousand dollars - to individual civilians injured or to the families of those killed.
Critics say the US needs to do more to account for and prevent civilian casualties.
"Obtaining better information about the rates and causes of civilian casualties can only enhance military commanders' ability to make sound judgments in the heat of combat - and improve their ability to ensure that US forces really are doing all they can to protect civilians," says Diane Orentlicher, professor of international law at American University's Washington College of Law.
"It would be impossible to obtain a perfect accounting of civilian casualties, in part because the civilian status of many victims may be doubted," says Professor Orentlicher. "But it doesn't make sense to respond to the proverbial fog of war by donning a blindfold."
In a report titled "Disappearing the Dead," the Project on Defense Alternatives in Washington asserts that in Afghanistan and Iraq "there were more than 85 incidents involving multiple civilian fatalities (sometimes running into the dozens) whose particulars were supported by multiple Western sources, on-site reporting, substantial visual records, and interviews with eyewitnesses, survivors, and sometimes hospital and aid workers."
As a result, writes Carl Conetta, the report's author, "The human cost of war ... and the prospect of collateral damage must figure centrally in any free decision to go to war."
Centrally or not, the prospect of civilian deaths does figure into US decisions to use deadly force, as Clinton and Bush administration officials pointed out last week in testimony before the commission investigating the 9/11 attacks.
The US uses a much higher percentage of precision weapons today than ever before. It is replacing cluster bombs (large numbers of which fail to detonate on impact and can later maim or kill civilians) with those that become inert after a short period if they don't explode when dropped or fired. Pentagon lawyers are involved in target planning to ensure the Laws of Armed Conflict are not being violated.
"If you talk to the Red Cross or most other observers, you'll find that [US forces] did a rather good job of avoiding or minimizing collateral damage" in both Iraq and Afghanistan. says Robert Goldman, who specializes in human rights and armed conflict at American University's Washington College of Law. (Civilian casualties in Afghanistan are as difficult to calculate as those in Iraq.)
This was not the case in previous wars. In World War II, tens of thousands of civilians were killed in single attacks. Mussolini terror-bombed Ethiopia; Nazi Germany indiscriminately bombed London; and the Allies firebombed Dresden and other German cities. Tokyo was firebombed, and the US dropped atom bombs on two Japanese cities.
"We've certainly changed our practices since World War II - everyone has - where the cities themselves were seen as targets," says Prof. Goldman.
Yet, in some ways, civilian casualties increasingly have become part of war - certainly part of the Pentagon's planning for what's called "asymmetrical war" fought against terrorist cells, insurgencies, and stateless organizations like Al Qaeda.
"In our war games, the bad guys gave up fighting us directly," says retired Air Force Col. Sam Gardiner, who has taught at the National Defense University. "They moved into cities. They attacked our supply lines with explosives. They wore civilian clothes. They took hostages. They responded to our new weapons by forcing on us the dilemma of killing civilians and of their killing of civilians."
That's exactly what's happening in Iraq today, and it portends the kind of dilemma US soldiers are likely to face if the White House and Pentagon civilians continue to send them into harm's way.
"Nowadays civilian casualties, and even specific incidents, can have a strategic effect on a conflict out of all proportion to their size, especially in an age of instant video transmission around the world," says military analyst Marcus Corbin of the Center for Defense Information in Washington. "If the Defense Department doesn't have its own estimates, even if [only] a broad range, it cedes the territory to opponents who may use wildly inflated estimates, which may unfortunately be readily believed by gullible foreign populations."
Of course, debates on the means and significance of calculating civilian losses in Iraq skirt a more central moral issue: Was the US justified in invading the country in the first place?
Yet once the fighting starts, that's no longer the question up for debate. Concerns then become what President Bush touched upon in his State of the Union address on the eve of war. He promised to spare - "in every way we can" - innocent Iraqis. But he also said, "If war is forced upon us, we will fight with the full force and might of the United States military - and we will prevail."