Dalrymple sees, in those who light candles after a terrorist attack, the very modern claim to be “spiritual but not religious”, as well as simple weakness:

The reason (I surmise) that so many people claim to be spiritual rather than religious is that being spiritual imposes no discipline upon them, at least none that they do not choose themselves. Being religious, on the other hand, implies an obligation to observe rules and rituals that may interfere awkwardly with daily life….

It would be difficult to prove it, but I imagine that all those candles are an encouragement to the very kind of people who commit the massacres that are the occasion for the exhibition. We cut their throats, or drive trucks into them; they light candles…They are mistaken, the terrorists; but they are not clever or deep thinkers…

So if you want more terrorist attacks, light a candle.