Conversation so far:
Who criticized Richard Pipes' approach?
The writings of Richard Pipes have provoked criticism in the scholarly community, for example in The Russian Review
Who was Richard Pipes?
Richard Pipes was an American academic who specialized in Russian history, particularly with respect to the Soviet Union, who espoused a strong anti-communist point of view throughout his career

Question: What was notable about his approach?
Self-contained rewrite: What was notable out Richard Pipes' approach?