The article is merely a restatement of an old truism, updated with current examples. The 'propaganda of the deed' has been an article of faith amongst terrorists since the anarchists of the late 19th Century. And although Harari's observations on relative casualties and the danger of overreaction are quite true (and not exactly insightful, having been pointed out by many over a period of decades), his argument carries the flaws of any broad generalization. As Omarali50 stated, terrorism is by its nature best understood in the context of its unique placement in the precise location, state, and region where it occurs. The 'propaganda of the deed' isn't always that. In some cases it is very likely to be a serious attempt at achieving a tactical or even strategic success based solely on the results of the attack without any messaging considerations from the perspective of the terrorists.