The latter part of September was deeply depressing: bombings in Iraq, scores dead in a Pakistani church, a new alliance of extremist Islamic brigades formed in Syria and the siege of a top-end mall in Nairobi, with at least 72 people killed by militants from the Somalia-based al-Shabab group.
Twelve years after the 9/11 attacks, our tolerance for such violence is higher. But every few months, there is an incident that is sufficiently close to home, literally when a soldier is killed on the streets of London, or figuratively when weekend shoppers are targeted, to provoke the existential dread that is the aim, by definition, of terrorism.
There are, however, several reasons to be more cheerful about the future than last month's events might suggest.