A review of Thomas Hayden (2004) “Roots of war” U.S.NEWS& WORLD REPORT
April 12, p.46-49.

War seems to be as old as time, but it may not be. Anthropologists have suggested that large scale warfare came from complexity that emerged after hunting and gathering societies. Once there was material storage of domesticated crops, raiding from other villages appeared. Thus, war became more common. About 3600 years ago, division of labor and related gave some villagers time to build fortresses, gated communities or other hideaways to fight off warring neighbors.

About 2000 years ago, professional standing armies began to appear. Permanent settlements also required armies to protect them. Homicide is no longer a personal offense, but a sin against the group and war is the outcome.

However archeologists suggest that warfare goes back to prehistory (perhaps 20,000 years or earlier.)
They suggest that unlike anthropologist’s belief that we can unlearn war, war is us. We are like other creatures. Spears show up at least 500,000 years ago.

Among other hominids such as chimps, environmental stress (shortage of food and space) can encourage warfare against other chimps. Humans appear to deplete resources (food, land, oil or related) and the outcome is war. Two or more groups fight over existing resources.

Archeologists note that peace can prevail for hundreds of years until there is environmental depletion. The loss of resources results in war. Much of the Middle East is of course about conflicting cultures, but it is also about oil and water.

However, archeologists and anthropologist agree that standing armies and military culture give rise to wars.
Elite can stroke the fires of ethnic division, border disputes, and related to spur the masses to give their lives to increase the riches of the elite. In other words, war is spin.

There is now some optimism among all parties about the future of war. Democracies are less patient with war than autocratic societies. The 20th century was filled with war and civil war. Millions died. However, the deaths relative to the population was much smaller than earlier centuries. We have more wars, but less die.

Peace unexpectedly appears as wild cards. Danes, Swedes, Norwegians were the raiding parties of the 9th century because of a population boom. When more resources appeared, the Scandinavians became more peaceful. New Guinea highlanders were continuously at war until a larger country with the resources to kill banned war.

Additionally, among baboons, a disease killed the aggressive alpha males and peace emerged. This continued on into the next generation.

War will not go away. However, the severity (save a large nuclear war) appears to be diminishing. Thus war appears to be a fixture of human existence, but the number of deaths appear to be lessening.