Dr. Cotler has been a professor of law at McGill University since 1973. He has been on a leave of absence since his election as a member of parliament in 1999.
Cotler is considered an expert on international law and human rights law and was once a counsel for Nelson Mandela as well as other well known political prisoners and dissidents. Cotler represented Natan Sharansky, who was imprisoned in the Soviet gulag for Jewish activism. After his release, Sharansky went on to become Israeli Deputy Prime Minister. Saad Ibrahim, an Egyptian democracy activist imprisoned by the Egyptian government, was represented by Cotler and acquitted in 2003.
Cotler's support for new security legislation, following the terror attacks of September 11, 2001 caused many critics to go silent.
Cotler is considered an upstanding member of the Canadian Jewish community, given his attempts to bring Nazi war criminals to justice and his strong support of Israel. He has also defended both Palestinians and Israelis against their own governments, and he participated in a minor role in the Camp David peace agreement between Israel and Egypt.
Though he intended his foray into politics to be a brief departure from his academic career, this changed when Prime Minister Paul Martin called upon him to enter cabinet.
Cotler recalled the conversation during which he was informed of the appointment as follows:
Martin: What do I do with a man who is both an expert on justice and human rights?
Cotler: I always thought justice meant human rights.
Martin: Good answer, minister of justice.