This early history of the Arab Nationalists' Movement, by a former member, is a slim and humble volume, promising only to "provide future studies in the field with a directive and an outline." It does raise more questions than it answers, but also offers a surprisingly rich view in surprisingly few pages of the milieu in which the movement began and operated. It also offers extensive quotations from the movements publications. I still put down the book a little unclear about the origin of the shift from Arab nationalism to a leftist Marxist-Leninism. Kazziha ascribes these shifts to individuals within the movement, and marks changes with political conferences and events. That does indeed offer a juicy prospective to future studies to shade in the more subtle contours.
Some of the best info in English that I could find on the development of the Arab Nationalist Movement and the Popular Front for the Liberation of Palestine. Shows, as the title indicates, Habash and others went from seeking a route to Palestinian liberation first through nationalism then slowly but surely to Marxism-Leninism. For a former ANM member, it is impressively dispassionate and insightful.