He was known for building bridges with other faith communities to advance mutual understanding and co-operation and to eliminate entrenched stereotypes, particularly ones rooted in religious teachings.

[3] Tanenbaum was dubbed "the human rights rabbi" for his work on behalf of Vietnamese boat people and Cambodian refugees.

A chance encounter with a former classmate, Harold M. Schulweis, who later became a distinguished rabbi and author, led to Tanenbaum to apply successfully to the Jewish Theological Seminary.

In 1952, he became director of the Synagogue Council of America, which was formed to represent the combined voices of Orthodox, Conservative, and Reform Judaism in the United States for policy and intergroup relations.

He served as the vice president of the White House Conference on Children and Youth, where he invited Rabbi Abraham Joshua Heschel to deliver a major paper.

[7] In 1983, Tanenbaum became director of International Affairs of the American Jewish Committee (AJC), where he focused on issues of human rights and humanitarian work.

He was awarded 15 honorary degrees and was honored by the International Council of Christians and Jews and the New York Board of Rabbis.