On the video, an old woman in a woolly hat in the Crimea is berating Russian soldiers. “Fear is the psychology of the slave,” she shouts. Then a man in black says, “You are a provocateur, babushka,” and shoves her. She tumbles over.

The ugly scene, watched 600,000 times on YouTube, highlights the strangest aspect of this conflict to date: very little bloodshed. As Vladimir Putin remarked after Russia’s invasion, “I cannot remember a single act of intervention without one shot.” One month later, three Ukrainians had died in the conflict. When Russians captured a Crimean air base last Saturday, Ukrainian soldiers – most carrying only wooden sticks – responded by singing Ukraine’s national anthem off-key. The casualty toll: one Ukrainian lightly injured. For contrast, more than 500,000 people died in the Crimean war of 1853-1856, and 75,000 in Hitler’s Crimean offensive of spring 1944. True, things could still go horribly wrong. Russian troops are massing on Ukraine’s borders. One incident could spark large-scale killing. However, there are reasons to think violence won’t erupt. Crimea today helps clarify why the world is becoming more peaceful.

The great theorist of this trend is Steven Pinker, professor of psychology at Harvard. His book The Better Angels of Our Nature says that annual deaths in battle dropped by more than 90 per cent from the late 1940s through the early 2000s. “The decline of violence,” Pinker writes, “may be the most significant and least appreciated development in the history of our species.” (Syria is the great current exception, accounting for most of the world’s deaths in conflict last year.)