Leak: Why Mark Felt Became Deep Throat, by Max Holland, University Press of Kansas, 285 pp., $29.95.

The timely publication of Max Holland's Leak, coming on the 40th anniversary of the Watergate break-in, promotes a needed reassessment of two myths about the Watergate scandal. The first myth is that the reporting skills and diligence of two Washington Post cub reporters, Bob Woodward and Carl Bernstein, uncovered the abuses of power in Richard Nixon's White House and led to the president's forced resignation in August 1974.

Holland, editor of the website Washington Decoded, acknowledges the limited importance of Woodward and Bernstein's reporting but contends that their contribution pales in contrast to that of Federal Judge John Sirica, Sen. Sam Ervin's investigation and public hearings, the testimony of White House aides John Dean and Alexander Butterfield, and the inquiries of the special prosecutor and the House Judiciary Committee (the latter when considering articles of impeachment).

The second, more important myth involves W. Mark Felt, the acting FBI associate director who in 1972 became Woodward's secret source, dubbed "Deep Throat." Holland rebuts Woodward and Bernstein's portrayal of Felt as a principled official who leaked information because he was concerned over the lawlessness of the Nixon White House. Felt's motives, as Holland convincingly documents, were more prosaic: He wanted Nixon to question whether he could trust Acting FBI Director L. Patrick Gray to control the FBI, thus leading the president to appoint Felt as the permanent FBI director, filling the vacancy caused by J. Edgar Hoover's recent death. Holland further documents that Felt withheld from Woodward some particularly explosive information about the White House attempting to use the CIA to contain the FBI's Watergate investigation. At other times, Felt passed on misinformation.

Holland's disclosure of Felt's insubordination does raise an important question: What emboldened this senior FBI official to betray his ostensible superior (while cunningly conveying the impression of a loyal acolyte), in the process unintentionally undermining Nixon's presidency?

The answer requires an understanding of the FBI's political culture forged during J. Edgar Hoover's 48-year tenure as the bureau's director. Since the mid-1930s, Hoover had expanded the FBI's role beyond federal law enforcement to operate surreptitiously as a political containment agency. FBI agents, accordingly, began to amass derogatory information about the personal and political activities of radical activists and prominent Americans, at times through the use of recognizably illegal investigative techniques. This information did not (and could not) advance legitimate law enforcement interests. Instead, Hoover and his senior aides exploited the information they acquired to advance their own bureaucratic and political agendas.

On the strict condition that the recipient not disclose the FBI as the source, the bureau leaked information to reliable reporters (including Walter Trohan, Don Whitehead, Courtney Ryley Cooper, Ed Montgomery, and Frederick Woltman), members of Congress (including Karl Mundt, Joseph McCarthy, James Eastland, Pat McCarran, William Jenner, and—yes—Richard Nixon), and other prominent Americans (including Ronald Reagan, Walt Disney, and Joseph Kennedy), as well as the House Committee on Un-American Activities and the Senate Internal Security Subcommittee. Felt's actions in 1972 and 1973 were exceptional only in the sense that his purpose was strictly personal and his target the current acting FBI director. He acted with the same sense of impunity as had his peers, in this case on the belief that his insubordination would not be discovered.

Felt's actions not only contributed to the unfolding Watergate affair but, more importantly in the long run, breached the wall of secrecy that had heretofore shrouded FBI operations from public scrutiny. The investigation of Nixon's role in the Watergate cover-up led to the exposure of his more serious abuses of the U.S. intelligence agencies: wiretapping prominent reporters, covert actions by the White House Plumbers, and, under the proposed Huston Plan, authorizing the use of illegal investigative techniques. In response, Congress in 1974—overriding President Gerald Ford's veto—enacted key amendments to the Freedom of Information Act that allowed reporters, activists, and scholars to obtain highly secret and revealing FBI records. That same year it enacted the Presidential Recordings and Materials Preservation Act, which ensured the preservation of the Nixon Oval Office tapes and transferred control over Nixon's presidential papers to the National Archives, and in 1978 it passed the Presidential Records Act, which defined presidential papers as public property and established the conditions and timing for giving the public access to them. And in 1975 it established special House and Senate committees that investigated and then publicized the abusive practices of the U.S. intelligence agencies from the 1930s through the '70s.

Combined, these actions ended FBI officials' absolute control over their agency's records, a change that eventually benefitted the research of Holland and others. Such research has expanded our awareness of how secrecy emboldened officials to violate privacy rights and the rule of law, and as such it offers a powerful, still relevant lesson in the adverse consequences inherent in blind deference to claims of "national security."

Athan Theoharis is a professor of history emeritus at Marquette University. His most recent book is Abuse of Power: How Cold War Surveillance and Secrecy Policy Shaped the Response to 9/11 (Temple University Press).