Robert A. Belfer is chairman and CEO of Belco Oil & Gas Corp. He was also a director of Enron Corporation, the US energy company which collapsed due to fraud -- see this article in US News and World Report about Belfer's involvement.
In 1997, Belfer made a donation to Harvard which, among other things, endowed a chair, the Robert and Renee Belfer Professorship of International Affairs, to which Stephen Walt was later appointed.
In early March 2006, Walt published a study (this paper) of the pro-Israel lobby in the US. A few days later, according to this article in Ha'aretz, Belfer "called the university [Harvard] and asked that Walt be forbidden to use his title in publicity for the study". Around the same time, Harvard forced Walt to change the frontpiece of the study (see this article). Were these events connected?