Man is a violent animal. This has always been so. But recently humanity has made progress in reducing large-scale conflict both among countries and within them. The exception is among the poor. Yet this is not a calamity that originates only from the poor or affects only the poor. On the contrary, both the origins and the impact of conflicts are global.

Taming mass violence is the theme of the World Bank’s latest World Development Report, which focuses on “conflict, security and development”. It is a fascinating document. Unfortunately, it is also far too long to obtain the attention it deserves. As I know from personal involvement in the first WDR, published in 1978, Robert McNamara, then president, believed these reports should be punchy and accessible. Excluding the annex table, the first WDR, which included what later became a separate report on the world economy, was 68 pages. The latest has 301 pages. Mr McNamara was right: less is more. But this report does have crucial messages.

First, happily, the direct impact