The death toll from the first world war was around 16m; the toll from the second world war was at least 55m. Yet even as the global population rose from 3 billion to 7 billion in the 50 years to 2010, the number of war-related deaths plummeted: that average was 180,000 a year during the four decades of the cold war; 100,000 a year in the 1990s; and 55,000 a year in the first decade of this century. The downward trend reflected the fact that, with rare exceptions, such as the Russia-Georgia war of 2008, states no longer send their armies to wage war against each other.Andrews notes, however, that deadly conflicts in Syria and South Sudan cast doubt on the meaning of those stats:
The bad news is that 2016 will confirm that the trend has reversed itself. Instead of fighting each other, states battle religious, ideological or ethnic insurgencies, or help allies supress insurgents—or fall apart in civil wars that defy easy resolution. The civil war in Syria alone has been enough to move the trend upwards: the country’s descent into chaos since 2011 has claimed some 250,000 lives; since December 2013 civil war in South Sudan may have cost over 50,000 lives.Is Syria an anomaly from recent trends, or does it reflect evidence that international war involving great powers is always possible? Even today, barely a week after a Syrian ceasefire agreement was announced, some experts fear the possibility of war between Russia and Turkey -- a NATO ally. The risks of escalation would be intensified in that scenario.
The apparent lesson is that neither scholars nor states can take non-violence for granted. The prevalence of violence and war went down for a number of reasons, but some of them require difficult diplomacy. And of course, great power restraint is a huge plus.