Last Saturday my friend Marla Ruzicka was killed by a suicide bomber in Baghdad. Just 28 years old, Marla was one of only a handful of foreign human-rights workers to set foot in Iraq this year.

A lot has been written about Marla's effervescence, her courage, and the way that she wore her heart on her sleeve. Far less has been said about how her canny approach to advancing the military's responsibility to civilians has the potential to change the future of warfare. In a way, Marla has been as underestimated in her death as she was in her life.

I'll be the first to admit that I failed to fully understand and appreciate the political importance of her work when she was alive. Several times over the last few days I've asked myself: Why didn't I do more to help her while she was still alive? Why didn't I get the big picture?

Not that what she was doing didn't amaze me: documenting civilian injuries and deaths while, at the same time, successfully working with U.S. military commanders to understand the human dimensions of their actions with the ultimate goal of seeking reconciliation through financially compensating victims and their families.

Marla conducted one of the earliest detailed Iraqi civilian death counts, going door to door to interview survivors. (Human-rights groups and news organizations today say that between 17,000 and 20,000 Iraqi civilians have died in the extended fighting.) In the days before she died, Marla was raising money to help send Rakan Hassan, a child from Mosul who had been orphaned and partially paralyzed by gunfire from a U.S. helicopter, to Oakland, California, to get surgery.

Marla had a powerful and graceful way of describing her work. “A number is important not only to quantify the cost of war but as a reminder of those whose dreams will never be realized in a free and democratic Iraq,” she wrote.

I knew about Marla's work but I didn't really comprehend how her research and her advocacy for victims could affect U.S. military policy until, a couple of days after she died, I called up a few of the folks I knew she admired and worked with: Bill Arkin, a civilian-casualties expert and military analyst with NBC News; Human Rights Watch's Marc Garlasco; and Sarah Sewall of Harvard's Carr Center for Human Rights Policy.

Arkin, Garlasco, and Sewall explained how much they had benefited from Marla's research into civilian casualties, which they believed was ultimately about setting a precedent for greater military accountability to noncombatants.

Garlasco explained to me how far we had come. “Through World War II, civilians were the objects of war,” he said, as exemplified by the United States' deliberate bombing of civilians in Germany (Dresden) and Japan (Tokyo and Hiroshima).

Today, by almost all accounts, the U.S. military tries to minimize civilian casualties, both for moral reasons and to win over hearts and minds. According to Garlasco, the Air Force estimates the number of civilian casualties it expects particular strikes will create, often changing or calling off strikes that will kill or injure too many civilians. “But once the war is done they never go back and check,” he added. “Marla's work was important because the Air Force could go back and figure out if their models are correct.”

Said Harvard's Sewall: “Marla knew how arbitrary and opaque the system was. She saw cases being denied for lack of a piece of paper, or a witness. Marla's data collection, her house-to-house surveys, offered a way to contribute to the understanding of when, where, and why civilians died. That's forward-looking.”

That kind of talk makes many in the U.S. peace movement nervous. Where's the line between advocating human rights and helping the military to wage war?

The truth is that the line between the two has never been particularly clear. The 1949 Geneva Conventions on the treatment of civilians (to which the United States is a signatory) states: “Civilians are not to be subject to attack. This includes direct attacks on civilians and indiscriminate attacks against areas in which civilians are present.”

Nobody would argue that the Geneva Conventions promote wars, though they certainly influences the way militaries wage them.

Marla took no position on the Iraq War once it started. This allowed her to connect with both GIs and generals -- one of whom she jogged with in Baghdad -- who had their fingers on the purse strings of funding to compensate victims, as well as access to information she needed.

While Americans will never speak with one voice about the U.S. occupation of Iraq, there's no reason for progressives and conservatives alike not to get behind Marla's proposal for the U.S. government to systematically track and study civilian casualties. Marla often said that her dream job would be to work at a desk at the U.S. State Department dedicated to tracking civilian casualties caused by U.S. military action.

What's needed is legislation to create such a desk. Congressional experts aren't yet sure whether it should be at the State Department or the Pentagon or elsewhere -- something Marla's closest friends on the Hill are working on now.

None of this is easy. Just sorting out who is a civilian and who is a plain-clothed insurgent can be complicated. But that tracking civilian casualties is hard does not make it impossible, as Marla proved in both Afghanistan and Iraq.

Marla's idea isn't just the right thing to do for moral reasons. Military expert Arkin argues that there is no longer a contradiction between military effectiveness and civilian protection, and that the military fully understands the direct and indirect effect of civilian casualties.

“The United States' practice of stiff-arming civilian victims and ignoring civilian casualties has enormous negative consequences,” he said. “We're seen as craven. We're seen as indifferent to civilian life. It harms our ability to operate on the ground.”

Those of us who knew and cared about Marla -- and everyone who didn't know her but has been moved by her work -- have an obligation to do what we can to realize her vision of closing the circle between the military and the innocent civilian population.

Michael Shellenberger is a writer and political strategist in El Cerrito, California. He first met Marla Ruzicka during a trip to Central America in 1995.