Professor Guenter Lewy, who as a young man had his father arrested by Nazis and then fought in the Jewish brigades later went on to write critically acclaimed books on history, such as the Catholic Church, the Native Americans, and the Vietnam War.
One of his latest books discussed the Armenian Massacres in Ottoman Turkey: A Disputed Genocide, which cast doubt on the genocide conclusions that the Armenians have posited.
https://www.youtube.com/watch?v=K-XxG2alJv0
He also wrote a book recently about Outlawing genocide denial in Europe and how troubling this was for democracy and free speech.