Garry Wills is a formidable Pulitzer Prize-winning historian, one of America’s leading public intellectuals and, over the last 50 years, our most important lay Catholic thinker and writer.

In his 28th book, “Bomb Power: The Modern Presidency and the National Security State,” he amplifies an idea he first raised a decade ago in “A Necessary Evil: A History of American Distrust of Government” -- that the dawn of the Atomic Age fundamentally changed our institutions of republican government.

Wills himself best condensed his thesis recently in the New York Review of Books:

“George W. Bush left the White House unpopular and disgraced. His successor promised change . . . [but] the momentum of accumulating powers in the executive is not easily reversed, checked, or even slowed. . . . The monopoly on use of nuclear weaponry, the cult of the commander in chief, the worldwide network of military bases to maintain nuclear alert and supremacy, the secret intelligence agencies, the entire National Security State, the classification and clearance systems, the expansion of state secrets, the withholding of evidence and information, the permanent emergency that has melded World War II with the Cold War and the Cold War with the ‘war on terror’ -- all these make a vast and intricate structure that may not yield to effort at dismantling it. Sixty-eight straight years of war emergency powers (1941-2009) have made the abnormal normal, and constitutional diminishment the settled order.”

“Bomb Power,” in other words, is an ambitious work, and while Wills is incapable of being anything but provocative and erudite, his book is thought-provoking but not entirely persuasive. As a one-time Jesuit seminarian, Wills, now 75, is a reflexive Thomist: That has made him very discerning of first causes and alive to the deeper meanings of texts, like the Constitution.

It’s not an outlook, though, that copes well with the reality of historical contingency -- and that is where this book is least satisfying. We did not build the bomb on a strategic whim: We built it because some of the world’s best physicists, including the instinctual pacifist Albert Einstein, told Franklin D. Roosevelt that if we didn’t, the Nazis would. The Manhattan Project with all its attendant secrecy was a consequence of that reality.

And yet, Wills argues, “only Congress can raise money. It cannot give to another branch what the Constitution limits to it. Executive actions that raise money apart from Congress, that hide the money raised from Congress, that fail to report all expended moneys to Congress, are all violations of the Constitution. The Manhattan Project was therefore a violation of the Constitution -- a thing perhaps understandable, or forgivable, as a onetime emergency measure in war. But as a standing policy . . . this creates a steady erosion of the constitutional system. The National Security State is in permanent constitutional crisis.”

Or perhaps it’s in a permanent state of tension -- between its republican ideals and the demands of a modern technological world. Wills is skeptical, for example, about the creation of the Central Intelligence Agency and quotes President Harry S. Truman’s anxiety over creating a “Gestapo.”

That’s all fine, but America’s lack of an active intelligence arm left it unprepared for World War II, and the reason why the CIA became the agency it did was largely because of the Soviet KGB, whose activities, we now know, were more extensive and effective than anyone realized at the time.

Wills similarly takes a jaundiced view of the Marshall Plan as an extension of U.S. power into Western Europe rather than merely an altruistic program of reconstruction. The alternative, though, would have been to allow communist parties to take power in Greece, Italy and, perhaps, France -- parties that essentially were wholly owned subsidiaries of Moscow.

Wills is on much firmer ground when he decries the national security state’s impact on open government. “Bomb power translates directly to information power,” he writes. “Secrecy emanated from the Manhattan Project like a giant radiation emission. Anything connected with the Bomb . . . was, as Sen. Daniel Patrick Moynihan said, ‘born secret.’ It was self-classifying. . . . And the power of secrecy that enveloped the Bomb became a model for the planning or execution of Anything Important, as guarded by Important People. Because the government was the keeper of the great secret, it began to specialize in secret keeping. . . .”

It was Moynihan, in fact, who first pointed out that the government’s classification of information, which should have decreased after the Cold War, actually grew by 62% after the Soviet Union’s implosion. “Accountability is the essence of democracy,” Wills writes. “If people do not know what their government is doing, they cannot be truly self-governing. But the National Security State assumes that the government’s secrets are too important to be shared . . . that only the President has all the facts, that we must simply trust that our rulers are acting in our interest.”

There’s a particularly interesting section on Dwight D. Eisenhower who, Wills argues, never would have given an OK to the Bay of Pigs invasion, though it was planned during his administration. Unlike John F. Kennedy, Eisenhower insisted that a functioning Cuban government in exile be in place before any covert military action. The author approvingly quotes Murray Kempton’s appraisal of Ike’s guiding rule: “Do nothing unless you know exactly what you will do if it turns out to have been the wrong thing.”

On the other hand, Wills takes Eisenhower to task for using the CIA to overthrow antagonistic governments in Iran and elsewhere and make unsuccessful attempts at regime change in Syria and Indonesia. Perhaps this was a manifestation of what Wills calls Ike’s “ruthlessness” or perhaps it was the wisdom of a one-time supreme commander of Western forces who believed covert operations were preferable to all-out conflict with a Soviet antagonist.

The author sums up his argument thus: “Perhaps, in the nuclear era, the Constitution has become quaint and obsolete. Few people even consider, anymore, Madison’s lapidary pronouncement, ‘in republican government the legislative authority necessarily, predominates.’ . . . Nevertheless, some of us entertain a fondness for the quaint old Constitution. It may be too late to return to its ideals, but the effort should be made. As Cyrano said, ‘One fights not only in the hope of winning.’ ”

Though Wills’ progress to that conclusion isn’t always as steady as one might wish, it remains a compelling one.

timothy.rutten@latimes.com