I grew up at ground zero during an age of terror. Just 10 miles upwind of my elementary school in Omaha, Nebraska sat Strategic Air Command headquarters, its proud motto posted outside the security gates: "Peace Is Our Profession." A group of radical nuns had once spray-painted "War Is Just a Hobby" on the sign before being dragged away in cuffs. But the certainty of Mutual Assured Destruction was no joke for those of us growing up during the Reagan years. Duck-and-cover drills were an annual occurrence, and air-raid sirens punctuated my play time at depressingly regular intervals.

In Thinking Beyond the Unthinkable: Harnessing Doom from the Cold War to the Age of Terror, Jonathan Stevenson, a professor of strategic studies at the Naval War College, attempts to understand why it was that the air-raid sirens never sounded their warning for keeps. His answer focuses on the role of people like himself (and me, for that matter), strategists in think-tanks who spent their days contemplating the absolute destruction of life on our little planet, ostensibly in the service of the Strategic Air Command’s motto. Stevenson’s purpose in delving into this particular intellectual history is to examine the lessons that come from thinking about doom on a daily basis and their possible relevance for us today, living in a new "age of terror." After tens of thousands of words evaluating deterrence through the threat of global annihilation, Stevenson proposes a kinder, gentler way of keeping America safe, one that relies on a more nuanced and pragmatic foreign and security policy devised by a new breed of think-tank denizens. As one who has lived under the shadow of nuclear deterrence and fought the shadowy terror of Al Qaeda, it should be unsurprising that I am an enthusiastic advocate of new thinking–and doing–in the pursuit of lasting peace.

Much of this story has been told before. Twenty-five years ago, Fred Kaplan, now a columnist at Slate, tracked the development of deterrence theory through the story of its intellectual architects in his wonderfully titled Wizards of Armageddon. Stevenson calls upon the same extraordinary cast of characters and chronicles their struggles to understand the most horrible way of war ever devised. In the wake of the devastation of World War II, the United States harnessed a small group of civilian intellectuals to think about how to use the power of the atom, unleashed at Hiroshima and Nagasaki, to keep the peace. Many of them came to work at RAND, the Research and Development Corporation, established in Santa Monica, California (a very nice place from which to contemplate Armageddon) in 1948. The most influential of them was probably Albert Wohlstetter, a mathematical logician born in Manhattan in 1913. His first important work for RAND, in 1951, was a study of how the Strategic Air Command should position its bomber bases; Wohlstetter’s conclusion, that they be dispersed as far as possible from the Soviet Union to allow maximum time and space to strike back, both imprinted the concept of second-strike deterrence in the nuclear lexicon and ensured that my childhood in Omaha would occur in the shadow of nuclear devastation. Wohlstetter’s 1959 Foreign Affairs article, "The Delicate Balance of Terror," was the public revelation of the logic of deterrence; published soon after the launch of Sputnik, it contributed greatly to an American appreciation of the nuclear sword of Damocles under which we lived.

Another important strategist was Thomas Schelling, who used game theory to inform his book The Strategy of Conflict. Shelling’s most significant contribution, Stevenson believes, was "his observation that those engaged in conflict would usually develop a common symbolic focal point–perhaps a physical or geographical point, perhaps a distinctive operational level of warfare–that dictated boundaries and limits." The Yalu River served this purpose in the Korean War, while the use of nuclear weapons itself was a boundary between the Cold War superpowers. The imposition of mass civilian casualties became a focal point in a number of conflicts with substate terrorist groups during the twentieth century; the violation of this tacit bargain by Al Qaeda–and the as-yet-unresolved search for a new symbolic focal point–is one of the things that marks a new phase in terrorism in our own time.

No description of the key thinkers of the nuclear age would be complete without reference to Herman "Genghis" Kahn, who served as a communications sergeant in Burma in World War II–after setting a record on the Army’s intelligence test–and began work for RAND in 1948. The author of Thinking About the Unthinkable, from which Stevenson draws his own title, Kahn coined the phrase "wargasm" to describe all-out nuclear war and, according to Stevenson, "was the first to insert the word only in front of comparative estimates of civilian deaths that ran into the millions." Although his greatest impact came in his advocacy of civil defense in order to make surviving a nuclear strike more conceivable (and hence make an attack less likely, as the enemy would be unable to destroy its opposition in one fell swoop), Kahn is most famous as the presumptive role model for the title character in Stanley Kubrick’s classic Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb.

Pleasant as it is to contemplate again the Doomsday Device that was the major plot twist of Strangelove, Stevenson correctly notes that "the higher calculus of nuclear deterrence is now more a historical curiosity" than a significant factor in international politics. But the story of the wonderful wizards of uranium gains something from being told anew in the wake of September 11. Although nuclear deterrence rested on the basis of a balance of terror–indeed, the story of its intellectual evolution is largely an attempt not to have to rely on holding civilian populations at risk of instantaneous destruction–the very fact that states have return addresses made the balance of terror relatively stable.

This was one of the many intellectual failings of the decision to invade Iraq in March of 2003. There are thousands of years of history to support the contention that deterrence works against states, and while the ruler of Iraq may have been a very bad man, there is little to suggest that he was anything but a rational political actor. Even if Saddam Hussein had gained control of nuclear weapons, self-preservation would have precluded him from using them, just as it had prevented a succession of Soviet leaders from unleashing this horseman of the apocalypse. Meanwhile, the risk that his proliferation would have been discovered and punished would have deterred him from giving nuclear weapons to sub-state actors, who had no territory at risk. September 11 did not, in fact, change everything, and one of the things that it did not change was the fact that states can be deterred.

Non-state actors, however, cannot be deterred so easily. Stevenson gets to this point about two-thirds of the way through Thinking Beyond the Unthinkable, and this is where the book begins to plow fertile new ground. The process by which Al Qaeda made the decision to attack the World Trade Center and the Pentagon is instructive:

Al-Qaeda’s shura, or council, sharply debated whether the shock of attacking the World Trade Center and the Pentagon would be worth the probable loss of Afghanistan as a base, and ultimately was persuaded that it was. So the threat of devastating retaliation against territory that had proven so reliable a deterrent during the Cold war was unavailing against al-Qaeda’s most powerful leaders. They seemed to view not only the destruction of September 11 but also the robust U.S. response as a catalyst to a self-perpetuating and intensifying jihad that would somehow realize the group’s violent eschatological vision of an America destroyed. In that light, any feasible punishment administered by the United States was not merely futile but, in fact, inspiring to the jihadists.

We now face enemies who not only are unconcerned that the fruit of their labors will be the destruction of everything they hold dear, but are absolutely gleeful at the idea. This is a new challenge, and not one which Kahn and Wohlstetter can help us with very much.

Unfortunately, they are not the only thinkers to have left this field fallow. The challenge of radical Islam is not something to which the United States devoted much thought as it grew stronger, encouraged by a reaction to globalization and by some of our own foreign policy decisions. In a judgment some readers will likely take personally but is almost certainly true, former RAND President Harry Rowen said that before September 11, "The scholars of Islam available in the West–certainly in the United States–were a pretty sorry lot." They did not, by and large, see this one coming.