Researchers said that the national mortality rate of those living in poor, war-torn countries has dropped since the end of the Cold War.
Reasons for the surprising decline in death rates include public health and humanitarian relief in war-torn regions that reduce mortality rates more quickly than wars can kill people, while warfare itself has changed, Andrew Mack, director of the Human Security Report Project, told AFP.
"Claims that national mortality rates in poor countries mostly decline during periods of warfare are deeply counterintuitive," noted the report, and nobody argues that war is good, said Mack.
"But the reality is that the death toll in most of today's wars is too small to reverse the decline in peacetime mortality that developing countries have been experiencing for more than thirty years."
Mack released the report, The Shrinking Costs of War, on Wednesday at the United Nations in New York. The project, based at Simon Fraser University in Vancouver, is funded by Britain, Norway, Sweden, and Switzerland.
A one-time professor and former security director to UN Secretary-General Kofi Annan, Mack admitted that precise data about indirect and direct mortality in wartime does not exist, especially in poor countries.
"It's incredibly difficult to determine whether people who die from disease and malnutrition wouldn't have died anyway," he told AFP.
But the researchers found that "in nearly 80 percent of countries reviewed in an analysis of under-five mortality rates in sub-Saharan Africa, death tolls were lower at the end of the war than at the beginning."
The report also cited a 2008 World Bank study showing that globally, median adult and infant mortality rates declined during wartime.
The report said that with some exceptions most wars are now fought with smaller weapons, are localized even within countries, and that there has been a 70-percent decline in major conflicts.
At the same time, it said, "more than 30 years of highly effective health interventions in poor countries in peacetime ... have cut death tolls from disease during wartime," while there has been "a dramatic increase in the level and effectiveness of humanitarian assistance to people in war zones."
"Most deaths in today's conflicts are caused by war-exacerbated disease and malnutrition, not war-inflicted injuries," said the report.
"There are still wars and instances of mass violence against civilians so deadly that they do, in fact, reverse the long-term decline in mortality rates," it noted, citing the Rwandan genocide as an example.
Meanwhile there is academic disagreement about how to measure war death tolls in Iraq, Darfur and the Democratic Republic of the Congo, and a wide discrepancy in reported numbers.
"It's an unfortunate fact that in countries with the greatest public health problems, there is the least amount of data on which to base decision-making," Harvard Medical School physician Ziad Obermeyer told AFP last month, during a disagreement with Mack over a study Obermeyer co-authored in the British Medical Journal.
That report concluded, "war causes more deaths than previously estimated, and there is no evidence to support a recent decline."
And this month, Mack and researchers with the International Rescue Committee publicly disagreed over the estimate of war deaths in the Democratic Republic of the Congo.
In an email to AFP, the IRC stood by its much-cited number of 5.4 million, while the Human Security Report argued that Congo's mortality rate is much lower.
At stake, said Mack, is continued funding by governments and non-government organizations that demand measurable results, as well as political support for peacekeeping and humanitarian measures.