The two polar-opposite alternative nuclear futures are abolition and cascading nuclear proliferation. Strategic analysts who worry most about abolition see signs of it in treaties that permit four-digit nuclear arsenals. It takes only a single additional, one-digit nuclear stockpile to trigger worst-case projections of nuclear cascades.

In between these poles lie two other alternative nuclear futures: sustainable nuclear deterrence and sustainable arms control. It’s hard to envision one without the other, but that doesn’t prevent warfare between these tribes. Supporters of sustained nuclear deterrence abhor abolition as well as cascading proliferation. In the United States, they sit on a three-legged stool – the nuclear triad — and will probably lose one of these legs. Many advocates of sustainable nuclear deterrence also oppose strategic arms reduction treaties and the CTBT, even though support for recapitalization – even at lower levels – will be hard to cobble together without new treaties.

Sustainable nuclear deterrence is the preferred end-state for countries that already possess the Bomb, especially states with declining national fortunes. In states that have lively debates over the utility of nuclear weapons and budget choices, definitions of sustainability are shrinking. Generational support for sustainable arms control, like nuclear deterrence, is also declining. When market shares for sustainable deterrence and arms control are both diminishing, what nuclear future will gain ground?

A fifth alternative nuclear future is slow-motion proliferation – which would be a continuation of our nuclear past, meshing with deterrence and arms control. This shared space has been made possible by the Nonproliferation Treaty regime. The NPT is built on two premises: that proliferation abhors a steady state, and that slow-motion proliferation does not lead to a sustainable nuclear future. To counterbalance slow-motion proliferation, the NPT points in the direction of abolition. Absent this pursuit, the NPT may not be sustainable, either.

Alternative Nuclear Futures: The Role of Nuclear Weapons in the Post-Cold War World was published in 2000, when ambitious hopes began to clash with new, harsh realities, including nuclear tests on the subcontinent. These essays, edited by John Baylis and Robert O’Neill, are worth reading (or re-reading) for the zeitgeist of debates over abolition at this juncture. Robert O’Neill participated in the Canberra Commission, which provided a blueprint for getting to zero. Here are some excerpts from his summary chapter:

My argument is that with the end of the Cold War the utility of nuclear weapons has changed. Formerly they were weapons of the top dogs: now they are becoming weapons of the underdogs…

The idea of marginalization of nuclear weapons sounds to the non-nuclear states very much like children being told to run off and play, and leave the adults to handle serious matters. Alternatively it seems like being told to shut up and stop complaining as if it were the complaints that are causing the problem, not nuclear weapons: just tiptoe around the arsenals of the nuclear-weapon states and almost treat them as if they were not there.

Marginalization will not be convincing to the non-nuclear states, and all the incentives for proliferation will continue to be in effect. Perhaps proliferation will be even easier if nobody is making a fuss about nuclear weapons. But marginalization is not likely to prove workable because the potential of nuclear weapons for causing death and destruction is simply too great. Nuclear-weapons crises will occur from time to time, resulting from a wide range of causes — accidents, defiance of international treaties, proliferation, and terrorism to name a few — and people will call for their control, reduction, or elimination.

A[nother] option is for the existing five major holders of nuclear weapons to recognize that their long-term security interests would be better served by ridding the world of nuclear weapons and begin to act on that basis. In other words they should be treated similarly to the other two major categories of weapons of mass destruction, biological and chemical weapons, and eliminated. The process of elimination could not be immediate. It would require a long series of gradual steps, each to be taken as confidence grows that security is actually being increased by a controlled passage towards elimination.