Why has warfare always been part of the human story?
From biology to belief, what explains the persistence of violent conflict?
What light can this shed on humanity's past - and its future?
There can be few more important but also more contentious issues than attempting to understand the human propensity for conflict. Our history is inextricably tangled in wave after wave of inter-human fighting from as far back as we have records.
Repeatedly humans have foresworn war, have understood its appalling risks and have wished to create more pacific, productive societies. And yet almost inevitably circumstances emerge under which war once more seems inevitable or even desirable