Rapidly shifting gears from translating Martial’s Epigrams to explicating the scriptures (What the Gospels Meant) to scrutinizing the classified memos of George Kennan is bound to induce wear and tear on the transmission of even the most tireless polymath’s intellectual lathe. So any writer as prolific, wide-ranging and thoughtful as Garry Wills is bound to, perhaps even entitled to, break down and craft something of a dud every once in a while. Bomb Power must be numbered among them.

With all the marks of a well-padded magazine article, Bomb Power surrounds a provocative, unconvincing thesis with the packing material of oft-told stories of the making of the American national security state since World War II. The thesis is that the command and control of nuclear weapons is not merely a crucial element of that state but that it singularly explains the national security state’s origins and development, particularly an erosion of constitutional government and the placement of overweening power in the president and the executive branch of the government. As Wills puts it, “The Bomb altered our subsequent history down to its deepest constitutional roots.” Since World War II, the United States has found itself in a “continuous state of impending or partial war,” with an attendant suspension of constitutional law that had theretofore been tolerated only in wartime emergencies. And “at the bottom of it all has been the Bomb.”

Throughout the book Wills wanders away from this informing argument into diverting, if familiar, anecdotes in the troubling story of the advance of the imperial presidency, aware perhaps that every time he returns to his thesis he strains to make the case. For example, he argues implausibly that in 1950, in the face of an admittedly nonnuclear threat from North Korea, Harry Truman sent American troops to war without congressional authorization in order to protect “his possible use of the Bomb in the future.” Wills offers no evidence for this causal assertion, so that while one might acknowledge that the Korean intervention had this consequence, there is every reason to be skeptical about Wills’s claim regarding Truman’s motives.

The bomb is a marvelous synecdoche for the national security state, but it is not its source, let alone the sole key to its history. The iconic architectural artifact of that state, the Pentagon, was completed in 1943, two years before Hiroshima. The lineaments of its military-industrial complex were in place during World War II, before the bomb was successfully tested, though, as Wills shows, the making of the bomb was a crucial proving ground for a number of its features—not least, tight secrecy and willful executive authority (in this case, in the hands of General Leslie Groves, the master of the Manhattan Project).

The origins of the national security state, as the term suggests, lie instead in an expansive conception of American national security, which in the early 1940s displaced among leading American policy makers the far more modest notion of national defense—which was imagined as continental security and was soon to be dismissed derisively as isolationism. As Henry Luce forthrightly observed in 1940, national defense as traditionally conceived could not justify American intervention in the wars raging in Europe and the Far East. The United States should enter the war, he said, to claim its destiny as “the most powerful and vital nation in the world.” This would mark the beginning of an American century built on “a system of free economic enterprise” in which the U.S. would become “the Good Samaritan of the entire world” and “the powerhouse of the ideals of Freedom and Justice.”

The cold war vastly extended the apparatus of the national security state, but given this breathtakingly broad conception of the national interest, its expansion might well have happened even if there had been no postwar challenge from Soviet imperialism—or no nuclear weapon on the hip of the president. National Security Council Report 68 (NSC-68), a 1950 document authored principally by Paul Nitze, was perhaps the most significant of the many secret memoranda articulating the ideology that informed the ballooning of the national security state in the early cold war years.

As Wills says, NSC-68 laid down arguments that “would take America into endless conflict in the back alleys of the world.” But he neglects to quote a passage in that document that jumps off the page:

The integrity and vitality of our system is in greater jeopardy than ever before in our history. Even if there were no Soviet Union we would face the great problem of the free society, accentuated manyfold in this industrial age, of reconciling order, security, the need for participation, with the requirement of freedom. We would face the fact that in a shrinking world the absence of order among nations is becoming less and less tolerable.

National security, by these lights, required American global hegemony for the purpose of establishing “order among nations,” even in the absence of a Russian threat.

If one can readily discern the beginnings of the national security state before the onset of the cold war, one must note as well the absence of an inclination to dismantle it to any degree in the interim between the collapse of the Soviet Union and the launch of the “war on terror” after September 11, 2001. (As Wills notes, the rate of government classification of documents increased dramatically in the mid-1990s.) The “war on terror,” of course, is a war without conceivable end and hence the perfect sort of war to ensure long-lived legitimacy for a robust security apparatus devoted to the ongoing pursuit of an American preponderance of power.

The most valuable element of Bomb Power is Wills’s assessment of the damage done to the Constitution, strictly construed, by the erection of the national security state. Here he engages in a running debate with conservative proponents of “original intent” such as John Yoo, a legal centurion of the Bush-Cheney White House. Yoo has claimed sovereign powers for the president, particularly in the role of commander-in-chief, rivaling those of Louis XIV.

Playing James Madison to Yoo’s Alexander Hamilton, Wills effectively mocks the “flimsy philological fantasy” that underlies Yoo’s often bizarre arguments. In Yoo’s interpretation of the Constitution, the exclusive power to declare war that is invested in Congress, for example, is not the power to initiate war but merely the power to announce the initiation of wars that might more properly be launched unilaterally by the president. This is the sort of thing that won respect and kudos at the Bush White House. As Wills observes, Yoo’s reading of the Constitution is almost as fantastic as his interpretation of the Geneva Con ventions in one of his notorious “torture memos” in which he argued that American interrogators’ infliction of “severe physical or mental pain or suffering” does not constitute torture if the infliction of such suffering is not the interrogators’ intended “objective” but is rather the necessary byproduct of an effort to extract information from a suspect.

But as Wills well knows, fanciful right-wing interpretations of the intentions of the founders have served less often as grounds for the executive evasions of legislative authority that are so crucial to the building of the national security state than have the loose constructions of an often liberal jurisprudence that is less wedded to history. Most prominent over the last century have been the arguments of those who contend that, whatever the founders’ intentions, the modern Amer ican nation requires a flexible construction of the Constitution, one adapted to the fresh challenges of our time and the responsibilities of a great power.

Liberal hero Franklin Roosevelt famously said that American government should not be constrained by “horse and buggy” interpretations of the Consti tution. This means a president with a much freer hand than Wills would allow. As Wills himself points out, it was not John Yoo but Woodrow Wilson, another liberal hero and a sharp critic of a reliance on “original intent,” who declared that when it came to the matter of foreign affairs, “the President is at liberty, both in law and conscience, to be as big a man as he can.”

As Wills ruefully admits, few people will take seriously his “fondness for the quaint old Constitution,” in which, as Madison said, “legislative authority, necessarily, predominates.” To regard the Constitution in this way, his critics will no doubt say, would be to burden the country with a “horse and flintlock” conception of the president’s role as commander-in-chief, according to which the president has insufficient authority to wage war and protect the nation’s citizens. To all appearances this appraisal would be shared by Leon Panetta, Eric Holder, Hillary Clinton, Nancy Pelosi, Harry Reid and Barack Obama, who have done little to roll back the innovative security doctrines and policies of the Bush administration.

And Wills’s liberal critics would be correct. Constitutionalism such as Wills and Madison offer is appropriate to a republic, not an empire.