He was promoted to research director at CNRS in 1995, and spent academic year 1995–1996 in the US as New York Consortium Professor (a joint position at Columbia and New York Universities and the New School for Social Research). 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.[12] Though the book was hailed due to its scope and perspective, it was criticized after 9/11 because it documented the failure of political Islamist mobilization in the late 1990s. Kepel answered his critics with his travelogue Bad Moon Rising in 2002.[13] He then analyzed in retrospect that failure as the end of a first phase of what he would later designate as the “dialectics of Jihadism”.