Oscar Wilde got it right when he said, “As long as war is regarded as wicked, it will always have its fascination. When it is looked upon as vulgar, it will cease to be popular.”
The same should be true of terrorism. It is wicked of course, but that is not the point. When you embark on mass killing you want to be wicked.
Terrorism is grimy and miserable, the acts of desperate and weak organisations, often despised by the masses they claim to represent. Depicting terrorists as being wicked could backfire, by implying that they are actually potent and threatening, capable of overthrowing states. Darth Vader was wicked, powerful, and incredibly cool. Terrorists are vulgar.
De Waal continues:
Far more than regular warfare, terrorism relies on the message—it is one part violence to ten parts terror. In an asymmetrical fight, a comparatively weaker actor targets civilians with mass violence not because he can win a victory but because he wants to sow terror in the enemy and inspiration in the hearts of followers....
Half the counterterrorist effort is also PR. Obviously, you need a huge operational intelligence effort. But you strike the strongest blow when you manage to preserve a state of normality and refuse to dignify attacks against you with the name of a war or a clash of civilizations. To accept the terrorist’s challenge is the geopolitical equivalent of a woman telling a stalker that she regards him as an existential threat.
Normality is the enemy of terrorist groups, and as they drift off the front page they grow ever less potent. Instead of panicking and calling them a "threat to our way of life" as George W Bush did in 2001, terrorists should be reminded how insignificant and impotent they are. They're not, after all, a threat to the way of life of Americans or Europeans, who carry on doing most of the things they did in the 1990s. They're not scary, they're dirty. Not impressively evil: vulgar.