The Middle East and the Challenge to the West (Columbia University Press, 2020) was reviewed by The New York Times as "an excellent primer for anyone wanting to get up to speed on the region”.

[4] His last essay, le Prophète et la Pandémie / du Moyen-Orient au jihadisme d'atmosphère, just released in French (February 2021), has topped the best-seller lists and is currently being translated into English and a half-dozen languages.

He then turned to the compared study of political-religious movements in Islam, Judaism and Christianity, and published in 1991 The Revenge of God,[9] a best-selling book which was translated into 19 languages.

He used the library facilities at NYU and Columbia to explore the scholarly sources for his best-selling book Jihad: The Trail of Political Islam based on two years of fieldwork in the Muslim World from Indonesia to Africa, which came out in English in 2001, and was translated into a dozen languages.

With his students, Kepel also co-edited Al Qaeda in its Own Words [15](2006) – a translation and analysis of chosen texts by Jihadi ideologues Abdallah Azzam, Osama bin Laden, Ayman al-Zawahiri and Abu Musab al-Zarqawi.

[18][19] In December 2010, the month of Mohammad Bouazizi's self immolation at Sidi Bouzid, in Tunisia, that sparked the Arab Spring, Sciences Po closed the Middle East and Mediterranean Program.

In 2016, La Fracture, based on radio chronicles on France Culture in 2015–16, analyzed the impact of Jihadi terror in the wake of attacks on French and European soil.

[26][27] In February 2016 he was appointed chairman of the newly founded Program of Excellence on the Mediterranean and the Middle East at Paris Sciences et Lettres (PSL) University, based at Ecole Normale Supérieure.

[citation needed] He is also director of the Middle Eastern Mediterranean Freethinking Platform at the Università della Svizzera italiana in Lugano, Switzerland where, since September 2018, he is an adjunct professor.

[32] His 2021 essay, "The Prophet and the Pandemic / From the Middle East to Atmospheric Jihadism", released in French in February 2021, topped best-seller lists and is currently being translated into English and a half-dozen languages.

According to Kepel, jihadi terrorism is caused by "the entrenchment of Salafism", a fundamentalist ideology in which most radical elements clash with the values of Western democracies and "are aiming for the destruction of Europe through civil war".

[citation needed] Kepel also referred to London as "Londonistan": "[the United Kingdom] gave shelter to radical Islamist leaders from around the world as a sort of insurance policy against jihadi terrorism.

[28] Kepel claims he belongs to the left in France and according to The New York Times he has "always been careful to distinguish mainstream Islam from the hard-line Islamist ideologues" and has "no sympathy for the xenophobia of the right-wing National Front".