One of the biggest threats in the contemporary world is the phenomenon of Islamic terrorism, which is increasingly becoming a facet of everyday life in Europe. In this article, I question whether it is possible to define Islamic terrorism as a form of counter-violence, according to how Jean-Paul Sartre presented this concept in Notebooks for an Ethics, and, as a consequence, whether it can be legitimized or justified. According to this argument, the freedoms that perceive themselves as oppressed can try to liberate themselves through violence, given certain conditions. However, with terrorism we do not simply face the paradox inherent to counter-violence. The key point, which clearly distinguishes Islamic terrorism from counter-violence, is the fact that behind this nihilistic fury there is no concept of freedom to be liberated.