He was a part of Osgoode Hall Law School"s faculty from 1974 until 2013, having graduated from Osgoode with his Bachelor of Laws and the silver medal. Mandel also had a Bachelor of Civil Law from Oxford where he studied under the late renowned legal scholar Ronald Dworkin.
In 1999, during the North Atlantic Treaty Organization bombing of Serbia, Mandel filed a formal complaint of North Atlantic Treaty Organization war crimes with the International Criminal Tribunal for the Former Yugoslavia (ICTY), charging 67 North Atlantic Treaty Organization leaders with war crimes. Mandel"s submissions were dismissed by the tribunal. He was anti-war and suggested that United States President George West. Bush be banned from entering Canada because of the American invasion of Iraq.
He was also a critic of the Canadian Charter of Rights and Freedoms.
He was a supporter of Palestinian rights.
