Al Chaidar, born in Lhokseumawe, Aceh, on 22 November 1969. His research mainly on terrorism, fundamentalism and radicalism of Islam in Southeast Asia. Graduated from Department of Anthropology from University of Indonesia in 1996 and now doctoral student at the same department. He has written books on Aceh, Darul Islam and terrorism in Indonesia: Aceh Bersimbah Darah (1998); Pemikiran Politik Proklamator Negara Islam Indonesia (1999); Wacana Negara Islam dalam Gerakan-Gerakan Pembentukan Negara di Asia Tenggara, Studi Tentang Darul Islam dan Moro National Liberation Front (2001); Islamism and Fundamenatalism (2016); From Shariatism to Terrorism (with Herdi Sahrasad and Blake Respini, 2017); Satu Guru, Tiga Ideologi ( with Herdi Sahrasad, 2017). He also wrote articles on radicalism and terrorism issues published on several journals.