The cold war has been called the “l(fā)ong peace”. In fact, the two decades after the collapse of the Soviet Union look a lot more peaceful. Indeed, it might make more sense to call 1991-2010 the short peace. It was an era that inspired some to speculate that the “better angels of our nature” might be gaining the upper hand. The bad news is that this short peace appears to be over.

To study the 1970s is to be reminded just how hot the cold war actually was. More than 2m battle deaths resulted from state-based armed conflict in the 1970s, compared with about 270,000 in the 2000s. For the US, Vietnam was a vastly more lethal war than Iraq (47,424 US combat deaths compared with 3,527).

After 1956, according to the Peace Research Institute Oslo, the peak years for battle deaths resulting from state-based armed conflict were 1971 (about 380,000 fatalities; and the years from 1982 to 1988, when the annual average was close to 250,000. Between 2002 and 2007 the average was just under 17,000.