 While teaching at Kansas State University as the Dwight D. Eisenhower Professor of War and Peace during the 1970–1971 academic year, Ambrose participated in heckling of Richard Nixon during a speech the president gave on the KSU campus.Given pressure from the KSU administration and having job offers elsewhere, upon finishing out the year Ambrose offered to leave and the offer was accepted.His opposition to the Vietnam War stood in contrast to his research on "presidents and the military at a time when such topics were increasingly regarded by his colleagues as old fashioned and conservative."