According to Ben Yagoda, a professor of English and journalism at the University of Delaware, in 1987, there are references to "red lines" in conflicts between Chad and Libya, and in a 1999 "New York Times" article, Muslim clerics in Iran are reported to draw a "'red line for the revolution' that no one should cross." These references occurred earlier as well, appearing a "Milwaukee Sentinel" article of 26 January 1984 regarding French intervention in Chad and a "red line" held by French forces in southern Chad.