Armed conflicts in the 21st century are less deadly than they have been at any time in the past 55 years, according to a three-year survey on warfare and violence.

The Human Security Report, written by a professor at the University of British Columbia, concludes that the number of genocides or mass murders has declined dramatically since the late 1980s, despite the large-scale killing of civilians during the past 11 years in Rwanda, Bosnia and Sudan. And it asserts that the number of coups or attempted coups has fallen by 60 percent since 1963. The report's research was funded by Britain, Canada, Norway, Sweden and Switzerland.

The report challenges the assumption that the world has become more violent with the proliferation of bloody conflicts in Africa and the Middle East. It also shows how the experience of the United States, which has lost more soldiers in Iraq than in any military operation since the Vietnam War, contrasts starkly with much of the rest of the world.

"Warfare in the 21st century is far less deadly than it was half a century ago," wrote the report's author, Andrew Mack. "The wars that dominated the headlines of the 1990s were real -- and brutal -- enough. But the global media have largely ignored the 100-odd conflicts that have quietly ended since 1988. During this period, more wars stopped than started."

Mack said international terrorism is the only form of political violence to worsen in recent years, but he challengedU.S. claims that terrorism constitutes the "gravest threat to international security" and citedstudies suggesting that the number of terrorist incidents has dropped in the past 20 years. "You see a decline in the number of incidents," Mack said in an interview. "But you see a major increase in the deadliness of the attacks and a major increase in attacks that kill large numbers of people."

Britain and France, the world's two greatest colonial powers, and the United States and the former Soviet Union, the chief Cold War rivals, fought the most international wars since 1946 -- a total of 65, according to the report. Australia, the Netherlands, Israel, Egypt and China each fought in at least a half-dozen conflicts during the same period.

Combat deaths have steadily declined since the 1950s, as conventional wars between major powers have given way to independence struggles and low-intensity conflicts. "In 1950, for example, the average conflict killed 38,000 people; in 2002 the figure was 600, a 98% decline," the report states.

Mack, a former senior U.N. adviser, said the decline in warfare is largely due to the end of colonialism, the end of the Cold War and an upsurge in U.N.-led peacekeeping efforts.