By Andrew Hay (Reuters) – A University of Arizona assistant education professor and her colleague have led weekly class discussions they hope will help aspiring teachers one day handle difficult conversations in the classroom. When the topic in November was Hamas’ attack on Israel and Israel’s retaliation in Gaza, the discussion led to complaints from students, a viral posting of a student recording of the class and a brief university-ordered leave for the educators. It was a lesson in how hard it is to address divisive issues in the United States, where protests and charged debates have erupt…