He writes on:
Tehran could not rule out the possibility that others with more and better nuclear weapons would strike Iran first, should it provoke a crisis or war. Judging from cold war history, if the Iranians so much as appeared to be readying their nuclear forces for use, the United States might consider a pre-emptive nuclear strike. Israel might adopt a similar doctrine in the face of an Iranian nuclear arsenal.
In these lines, Posen makes a very strong case against his own thesis. Do we really want to re-create the nuclear nightmare of the late 1950s and early '60s: the fear that one side in a confrontation might launch a nuclear first strike—and the equally grisly fear that the other side would pre-empt the strike by launching its own first strike first? Wouldn't everyone be better off it we could stave off the condition that might trigger even this possibility—that is, if we could prevent an Iranian nuclear arsenal from coming into being?
This point raises another, more basic fallacy to Posen's argument. He ignores the possibility of accidental or unauthorized nuclear war. Cold War history is also chockablock with tales of U.S. early warning radar systems detecting a massive Soviet missile attack—when, on further examination, it turns out the radar had only picked up a flock of geese or had simply malfunctioned. There are also many cases of American military commanders (note: not "crazy mullahs," but "rational," Western-educated generals) who were eager to launch nuclear weapons but didn't because they were either politically constrained by the hierarchy of command authority or physically prevented from doing so by locks (known as "permissive action links" or PALs) that could be opened only by authorized orders.
If Iran builds nuclear weapons, how good will their early warning systems be; how firmly will their command hierarchies be enforced; will they have PALs? Steve Coll reported in The New Yorker last month how close India and Pakistan came to nuclear war just four years ago. They were on the brink of conventional war, and had that happened, Coll's sources told him, nuclear war may have been inevitable, because Pakistan's control over nuclear weapons was loose, its doctrine on nuclear use was nonexistent, and its urge to launch a nuclear strike would have been overwhelming—both as an alternative to surrendering and to pre-empt India from launching its own nuclear strike.
Posen is not alone in his views. They fall into a school of thought on nuclear deterrence associated with Kenneth Waltz, professor of political science at Columbia University, who in 1981 wrote a monograph titled The Spread of Nuclear Weapons: More May Be Better. Waltz wrote, "In a conventional world, one is uncertain about winning or losing. In a nuclear world, one is uncertain about surviving or being annihilated. … When these are the pertinent questions, we stop thinking about running risks and start worrying about how to avoid them. …The gradual spread of nuclear weapons is more to be welcomed than feared."
Waltz's premise, as stated to one reporter, is that "the only thing a country can do with nuclear weapons is use them for a deterrent. And that makes for internal stability, that makes for peace, and that makes for cautious behavior."
The problem is that, while Waltz and many other reasonable people might think nukes are good only for deterrents, others—including U.S. secretaries of defense and strategic air commanders over the decades—have thought nukes can be effective tools of war-fighting as well. In the United States, their influence has tended to be diluted by politicians and diplomats. In other less open and democratic countries, who knows?
But Waltz's position has been most solidly rebutted, on different grounds, by Scott Sagan, professor of political science at Stanford University. (The two have published a book together, in which they debate their views.) The spread of nukes, Sagan argues, doesn't eliminate human error; it "only makes the inevitable mistakes more deadly."
Waltz is a philosopher of international relations; his book, Man, the State, and War, has been a classic in the field for 40 years. Sagan is not only a political scientist but an archival historian; his book, The Limits of Safety, is the most comprehensive account of accidents that nearly triggered nuclear war.
Posen doesn't take Waltz's position, but he leans in that direction. In the real world, facing real risks, I'll go with the historian who assesses risk and human error over the philosopher who presumes reason and rationality.