By Gabriel Schoenfeld, W.W. Norton & Co. Inc., New York and London, 309 pages, $27.95

Just a few weeks ago, on June 9, the U.S. Court of Appeals for the Second Circuit reversed a district judge’s ruling that the City of New York must disclose the police department’s file on its surveillance, preceding the 2004 Republican National Convention, of suspected trouble-makers. That unanimous decision testifies to the enduring relevance of Gabriel Schoenfeld’s “Necessary Secrets.”

It illuminates the conflict between the citizenry’s “right to know,” an imperative of true democracy, and the “diametrically opposed” need of the government, sometimes a matter of survival, to keep certain matters safe from the public eye.

It becomes evident early in the book that the author, a political scientist currently a senior fellow at the Hudson Institute in Washington, D.C., and a resident scholar at the Witherspoon Institute in Princeton, N.J., has an axe to grind.

He thinks, first, that the government should be tougher in enforcing statutes (e.g., the Espionage Act of 1917 and the Comint statute of 1950) and policies protecting official secrecy. Secondly, he believes that the press should show greater restraint in its treatment of news whose publication can threaten the public good.

Not every reader will concur in the author’s views, but few will deny that his presentation deserves careful consideration.

The clash between the opposing values of transparency and secrecy arises typically out of the unauthorized disclosure by a government officer or employee. The author points out in his introduction that in this country “leaks to the press are a well-established informal practice” and “leaking has become part of the normal functioning of the U.S. government.” Yet he emphasizes the distinction, not always easy to perceive, between harmless leaks and “the disclosure of highly sensitive national security secrets to the press.”

As he must, Schoenfeld concedes that official secrecy can do harm as well as good. It provides an easy way to hide what should not be hidden. “We face the ineradicable potential,” he writes, “for misuse of secrecy to obscure incompetence and to promote illicit ends.”

He cites Watergate and Iran-Contra as prime examples of such misuse. Appraising President Nixon’s role in the former affair, he concludes, “No other president in American history has given secrecy such a bad name.”

An early chapter of the book demonstrates that the founders of the Republic accepted secrecy as a premise of organized government. The Continental Congress excluded outsiders from its sessions. The Constitution itself was drafted behind closed doors. That document’s §5 of Article I lets each House of Congress exclude from its published journal “such parts as may in their judgment require secrecy.”

The author attributes to James Madison the observation, “Our political system was thus born in secrecy.” The point so made enables Schoenfeld to dispose of the contention that the First Amendment grants absolute protection to the disclosure of leaked secrets.

He accuses publishers, particularly The New York Times, of unjustifiably “wrap[ping] themselves in the mantle of the First Amendment” as they “imperil the public” by “publishing whatever they choose no matter the cost.”

The “seemingly unequivocal words” of the amendment, he argues, “are fully compatible with legal restrictions on what journalists can and cannot say in print.”

As the book proceeds, it takes up a series of episodes in which leaks have actually or allegedly threatened national security and, in most cases, gone unpunished.

To his credit, the author does not leave out instances reflecting discredit on the enforcement process. In 2005, for example, a Defense Department employee and two lobbyists for the American-Israel Public Affairs Committee were indicted for violations of the Espionage Act. The prosecution, which the author calls “misbegotten,” ended in the withdrawal of the indictment after the emergence of fatal, in some cases embarrassing flaws in the case. They included “blatant evidence of anti-Semitism in the FBI.”

Does the Pentagon Papers case belong in the same category? The author says that it arose out of “the most consequential leak in American history.” The Supreme Court in 1971 vacated an injunction forbidding The New York Times and the Washington Post to publish a voluminous file lifted by Daniel Ellsberg from the archives of the Defense Department. The author concedes that all of the documents were at least three years old and that “no current operational secrets were disclosed.”

To criticize the outcome, he resorts, not exactly wholeheartedly, to the argument that the case demonstrated “to American allies and adversaries alike that the U.S. government was having severe difficulty keeping its secrets secret.”

The book advances an argument novel at least to this reviewer. Schoenfeld points out that statutes and regulations protecting governmental secrecy emanate from legislators and officers who owe their positions to the democratic process.

It follows, he contends, that those who leak sensitive material and those who publish it defy that process. Journalists in such instances, he maintains, “are not surrogates for the public but usurpers of the public’s powers and rights.” He calls Ellsberg’s leak of the Pentagon Papers “an assault on democratic self-governance itself.”

Schoenfeld’s book does not come up with a formula for balancing the desirability of transparency against the needs of national security.

The author’s studious accounts of episodes calling for such a balancing, however, together with his arguments, will help readers appreciate what is involved in attempting to resolve conflicts that one can be sure will continue to occur. The book, although falling short of perfection in objectivity, unquestionably makes a contribution.

Walter Barthold has retired from the practice of law in New York City.