In the early 1970s, Cooper was involved in visiting SovietRefuseniks, ultimately leading to his work to open the first Jewish cultural center in Moscow in the 1980s, and lecturing at the Soviet Academy of Sciences and the Sakharov Foundation later in his career.
In 1977, he came to Los Angeles to work with Rabbi Marvin Hier who founded the Simon Wiesenthal Center. Together with Rabbi Hier, Rabbi Cooper has met with world leaders, including Pope Benedict XVI, presidents, and foreign ministers.
In 1990, Cooper gave Public Enemy's Chuck D a "conscious-raising” tour of the Holocaust Museum. “I think Chuck has an open mind on certain levels,” he said. “He may be ignorant of some of our history, but he’s not an anti-Semite.”[2] The tour was in response to Rabbi Cooper's frustration with the American music industry,[3] specifically the fact the record labels were releasing music with lyrics that were bigoted and/or racist.
In 1992 he publicly commented about the lyrics to Ice Cube's diss trackNo Vaseline, in which Cube advocated violence against Jerry Heller, whom he identified as a "white Jew": "We're not asking Ice Cube to mask the reality of the streets," he said. "By all means flag the social problems, but don't exploit them by turning a professional spat between a former manager and an artist into a racial dispute." Cube responded, "It's wrong for the rabbi to call me anti-Semitic. I respect Jewish people because they're unified. I wish black people were as unified."[4]
In 1992, and again in 2003, he helped coordinate international conferences in Paris on antisemitism cosponsored by UNESCO.
In 1997, he coordinated the center's international conference, "Property and Restitution-The Moral Debt to History" in Geneva, Switzerland.[5]
He has testified before the United Nations in New York and Geneva, presented testimony at the US Senate, the Japanese Diet, the French Parliament, the OSCE and is a founding member of Israel's Global Forum on Antisemitism.[6]
In 2003 Rabbi Cooper served on the transition team for Governor-elect of California Arnold Schwarzenegger.[7]
In 2005, Rabbi Cooper participated in an international conference on terrorism convened in Madrid on the first anniversary of the infamous train bombings in Spain's capital.