Mark Riebling writes on national security, secret policy and covert operations. He directs the 9/11 Initiative at the Manhattan Institute for Policy Research, and as co-founder of the Center for Policing Terrorism, he has helped city and state police build intelligence services and fusion centers to counter 21st-century threats.

He is the author of Wedge: The Secret War between the CIA and FBI (Knopf, 1994; Simon and Schuster, 2002). In a Washington Post feature on the reissue of Wedge, Vernon Loeb reflected: “If [Riebling's] thesis - that the FBI-CIA rivalry had 'damaged the national security and, to that extent, imperiled the Republic' - was provocative at the time, it seems prescient now, with missed communications between the two agencies looming as the principal cause of intelligence failures related to the Sept. 11, 2001, terrorist attacks.” Former U.S. attorney Andrew C. McCarthy, who led prosecution of the 1993 World Trade Center bombers, wrote in 2004 that “Riebling’s thesis… has now become conventional wisdom, accepted on all sides.”

Mark Riebling’s writings are used as research and instructional texts at the Air University (Maxwell AFB); Army War College; Naval Postgraduate Institute; CIA Center for the Study of Intelligence, Centre for Counterintelligence and Security Studies (London), and the Belfer Center for Science and International Affairs at the John F. Kennedy School of Government, Harvard University.

"A brilliant book. Outstanding research and superlative presentation of the dramatis personae. An anecdotal and extremely well written account -- as informative as any treatise and as entertaining as the best espionage novels." -- Kirkus Reviews.

"Riebling successfully re-creates the life-or-death atmosphere of the half-century of American confrontation with the Soviet Union. Mr. Riebling succeeds as well in persuading the reader that the FBI-CIA conflict was a more important piece of the cold war mosaic than heretofore noted by historians." -- Michael R. Beschloss, New York Times Book Review.

"A lively and engaging narrative of interagency bungling, infighting, malfeasance and nonfeasance, providing fresh and well-rounded portraits of well-known (and ought-to-be-well-known) agents -- drawing on scores of original and rewarding interviews." -- Richard Gid Powers, front page, Washington Post Book World.

"Well researched, wittily written, full of good judgments. In a large and growing field, WEDGE will join the shelf of those few books which meet both standards of scholarship and expectations for insight and entertainment at a high level." -- Robin Winks, Professor of History, Yale University.

"There are few books that adequately cover this subject. Much of what passes for 'the literature' is overblown, conspiracy-addled and fragmented. But Mark Riebling, a historian, has made a valiant effort to piece it all together in Wedge. The fact that he has taken great pains to avoid using anonymous sources is just one of a number of reasons why serious students of this nation's haywire-rigged counterintelligence effort should read Wedge Refreshingly unlike most spy literature, the cumulative effect of his tales is staggering." -- John Fialka, The Wall Street Journal.

"Gripping history." -- Andrew C. McCarthy, Commentary Magazine.

"Any illusions that the two organizations simply mirror each other are thoroughly shattered. Riebling meticulously traces the continuing conflict and its consequences, which sometimes took the form of Keystone Cop episodes but more often were deadly serious." -- Houston Chronicle.

"A surprisingly fresh, coherent, well-written and persuasive analysis. Striking conclusions, a succession of colorful adventurers, and highly provocative speculations which have the unsettling ring of plausibility." -- Pittsburgh Post-Gazette.

"Incisive.... Riebling shows how personalities shaped the struggle between the agencies, and how the struggle hampered intelligence. There's much here to stimulate discussion." -- Tampa Tribune.

"Riebling brings forth many new angles, thanks to his entree to a web of retired agents. A well organized, engaging account." -- Booklist.

"Serves up some juicy insights. The book is full of colorful and strong characters as well as entertaining description and lucid writing." -- Toledo Blade.

"Meticulously researched yet entertaining." -- San Francisco Chronicle.

"An exceptionally readable and coherent account, exhaustively sourced." -- John Robbins, former CIA officer, The Palm Beach Post.

"Riebling's impressive documentation is chilling, sobering, and thought provoking." -- Virginia Quarterly Review.

"Riebling's writing is articulate and reflective. He explains the Angleton view so competently that it finally makes sense on its own terms." -- BookBase Online.

"In Wedge, Mark Riebling's compelling and exhaustively researched history of the two intelligence giants, the depth of [the] inter-agency animus -- and its pernicious effects -- becomes distressingly clear. Riebling has avoided tarring the late FBI boss [J. Edgar Hoover] with the kind of sensationalist touches common to recent biographies. He is respectful of those he believes played the both wisely and well. If a heroic figure emerges from Wedge it is the late James Jesus Angleton, the CIA's controversial director of counterintelligence for more than 20 years. Riebling partially rehabilitates Angleton from the drubbing he's taken in recent books such as David Wise's "Molehunt," in which he is depicted as disrupting his own agency in a futile, paranoid search for a nonexistent moles. Riebling has crafted a thorough history of the fatally flawed CIA-FBI marriage through interviews with many of the key players and reams of internal documents, many of them recently declassified. Wedge accords the current crisis an appropriate historical context." -- Scott Ladd, Newsday.

"I cannot do this book justice, other than to say that I had never understood the depth and stupidity of the bureaucratic hostility between the FBI and the CIA until I read it -- and that it should be required reading for every senior CIA manager. From the FBI's failure to communicate its very early knowledge of Japanese collection requirement on Pearl Harbor via the Germans, to the assassination of President Kennedy, the World Trade Center bombing and the Aldrich Ames case, this book makes me ashamed and angry about how bureaucracy and secrecy subvert loyalty, integrity, and common professional sense." -- Robert Steele, former CIA Officer, President, Open Source Solutions.