What is the author's tone in Sleeping with the Devil: How Washington Sold Our Soul for Saudi Crude by Robert Baer?

The tone of Sleeping With the Devil is subjective. The author is writing about his own experiences and presenting his own opinions. He obtains much of his information from conversations with people and from intelligence sources. He analyzes the information and presents his conclusions. The problem is that there is no way for the reader to substantiate any of the information, such as the story about Adnan Khashoggi leaving a briefcase with one million dollars in cash at the San Clemente home of Richard Nixon several days after he is elected President. There is no way to document the conversations he had with different members of the Muslim Brotherhood or Wahhabis clerics or anybody else. Some of the information comes from Russian and other intelligence reports, which obviously can't be documented, and in places where information could be documented, it isn't. There are no footnotes or credits in the book except for the Acknowledgments page. Because of the sources of Baer's information, it is understandable that there is no documentation presented and also because of this lack of documentation, the reader has to be careful of how the information is interpreted. Baer presents a cohesive picture of the relationship between Saudi Arabia and the Wahhabis and the oil depending on the United States but without any sources that the reader can check. The reader has to wonder how much of the information is fact and how much is opinion.