The 82-year-old historian and rabbi has been at the center of events that shape American Jewish life for more than 50 years. He is the former president of the American Jewish Congress, and helped to found the movement called Peace Now in Israel. His 1959 book, The Zionist Idea, is considered a classic. Last year he wrote his memoir A Jew in America: My Life and a People's Struggle for Identity. His new book is The Fate of Zionism: A Secular Future for Israel and Palestine.