The article analyzes the prospects of the presence of the terrorist organization “Islamic State” in Libya after the defeat of 2016. Although the Libyan authorities, with help of the international community, managed to deprive the ISIS of its stronghold in Sirte in 2016, the radical organization was able to recover, reorganize and once again claim to determine the future of Libya and the Sahel. The relevance of this study is due to the influence that the growth of radicalism in Libya has on international security, the environments in the Sahel and neighboring Arab and African countries. The situation is complicated by the fact that in Libya, from 2011 to the present time, there is a devastating civil war on calling into question the very existence of the Libyan state, creating a ground for the spread of radicalism and crime in the region and in the Mediterranean as a whole. Based on the analysis of reports from Libyan and Arab news agencies, data from European and American analytical centers, the authors draw conclusions about the prospects of the ISIS’s presence in Libya. Its future will depend on the success of state reconstruction. Organizations of this type emerge and can develop where national states are collapsing and a vacuum of power, chaos and lawlessness arise. The measures taken in the last year by the Libyan National Army to liberate southern Libya from terrorists and to open its oil fields may become a real obstacle for the ISIS there. If these measures have an effect, the “Islamic State” in Libya may face the impossibility of continuing its previous activities in the Libyan Fezzan. Conversely, if a new round of inter-tribal and inter-ethnic struggle breaks out in Fezzan as a result of the disruption of social and power balance due to the LNA campaign or inability of the Government of National Accord and Libyan National Army to work together, the “Islamic State” will only strengthen its positions. The ISIS has clearly demonstrated that it is able to gain and accumulate resources in conditions of instability. © 2019, Russian Academy of Sciences. All rights reserved.