The Unconquerable World

With the end of the bipolar Cold War order, some have argued that the balance of nuclear terror can actually be extended and strengthened by proliferation.

Just as nuclear weapons stopped the two superpowers of the Cold War — the Soviet Union and the United States — from fighting a hot war, so, it is suggested, they can immobilize 10 or 20 or 30 nuclear powers, in a grand peace based on universal terror.

Proliferation undermines stability — in every sense of that word. In the first place, though, it destroys strategic stability.

Strategic balance during the Cold War was supposed to depend on the attempt to maintain a rough equality between the forces of the two sides.

In a world of many nuclear powers, this goal becomes unreachable.

If country A and country B were to painstakingly craft a stable nuclear balance, it could be overthrown instantly by any nuclear-armed country C that suddenly allied itself with one or the other.

The necessary changes in nuclear targeting could be accomplished in just a few hours or days.

Even in today's world of eight nuclear powers — or perhaps nine, if North Korea's claim to possess nuclear weapons is true — some of the imbalances inherent in nuclear multipolarity are evident.

There is little hope of balance, for example, in the four-sided relationship of the United States, China, India and Pakistan.

India has stated that it became a nuclear power to balance nuclear-armed China, by which it was defeated in a conventional border war in 1962.

In turn, Pakistan became a nuclear power to balance India. If India seeks again to balance China, however, will Pakistan seek to keep up?

China, moreover, has supplied nuclear technology to Pakistan. And Pakistan has supplied some to North Korea, receiving missile technology in return.

Will India therefore feel compelled to build a nuclear arsenal that equals both China's and Pakistan's?

The United States meanwhile has decided to build national missile defenses, which — if they turn out to work — will erode or nullify China's capacity to strike the United States.

China has already said that it will respond by building up its still modest nuclear forces. That will put additional pressure on India.

Nor can we forget that Russia may, at any point, step into the picture with its still-huge arsenal.

The spread of ballistic- and cruise-missile technology, whose proliferation is as predictable as that of nuclear technology, compounds the problem geometrically.

In the second place, proliferation is bound to undermine the foundations of technical stability. During the Cold War, the United States and the Soviet Union sought a kind of safety in the policy of mutual assured destruction.

In practice, however, they found that their nuclear command-and-control systems were so vulnerable to a first strike that the retaliation required by the doctrine could not in fact be assured.

To cure the problem, the two governments resorted to policies of "launch on warning." Each planned to launch its retaliatory strike after receiving a warning that the other side had launched its first strike — but before the missiles had arrived.

This system placed severe time pressure on any decision to launch in retaliation, increasing the risks of accidental war.

The presidents of the United States and Russia were — and still are — required to make these decisions within five minutes of receiving warning of an incoming strike. The pressures on Russia, which now faces a technically superior U.S. force, have grown especially severe.

If the United States and Russia, with all their resources and an ocean between them, cannot guarantee the survival of their command-and-control systems, is it reasonable to expect that smaller, poorer nations — facing many potential adversaries, with little or no warning time — will accomplish this?

The warning time between India and Pakistan, for instance, is effectively zero.

For them, not even launch on warning is possible. The requirements for nuclear stability under the doctrine of deterrence are thus altogether lacking.

In the third place, what the experts call arms-control stability — meaning conditions favorable to negotiated limits on or reductions of nuclear arsenals — would be destroyed.

During the Cold War, the United States and the Soviet Union, unable to agree on numerical offensive limits, built up their collective arsenals to the preposterous collective level of some 75,000 nuclear warheads.

In a multipolar nuclear world, though, arms-control agreements are exponentially harder to achieve. How could 20 or 30 nations — few of whom trusted the others or were sure what they were doing — be able to adjust the scores of nuclear balances among them?

Containing proliferation — if someone should wish to return to that policy somewhere down the road — would be a pipe dream.

How would, say, the 20th nuclear power persuade the 21st that building nuclear weapons is a bad idea?

In the fourth place, multiplying nuclear arsenals would increase the danger of nuclear terrorism. A world of proliferation would be a world awash in nuclear materials. Terrorists who acquired them would be indifferent to nuclear threats from others.

The balance of terror depends on fear of retaliatory annihilation — but many terrorists have no country of whose annihilation they are afraid. They are unafraid to lose even their own lives — and blow themselves up with the bombs they aim at others.

The terrorist bent on self-immolation with a weapon of mass destruction is the nemesis of balance. Deterrence has no purchase on the dead.