The 1960s were equally remarkable. As a presidential candidate in 1960, for example, John F. Kennedy foresaw "ten, fifteen, or twenty nations" acquiring a nuclear capability by the 1964 election. The following year, the Kennedy administration was so certain a Chinese nuclear test would trigger a global wave of nuclear proliferation that it considered simply giving Beijing's neighbors "defensive nuclear weapons." Although not a single additional nuclear power emerged by 1963, President Kennedy remained "haunted by the feeling" that there would be fifteen or twenty of them by 1975 and possibly twenty-five by the end of that decade.

And yet nearly half a century after the Cuban missile crisis there are only nine nuclear-weapon states, five more than when Kennedy was elected and two of which already had advanced nuclear weapon programs during his presidency. During the same time interval, four states have voluntarily given up their nuclear arsenals and an estimated forty nations have not built them despite possessing the technical capability to do so.

The Future of Proliferation

Still, just because nuclear forbearance has been the norm thus far doesn't necessarily mean this will continue into the future. In fact, according to Shavit, an Iranian bomb would "force Saudi Arabia, Turkey and Egypt to acquire their own." Similarly, President Barack Obama is "almost certain" that if Iran gets nuclear weapons, its neighbors will be "compelled" to do the same.

Once again, there's not much evidence to support these assertions. Although a few countries have built nuclear weapons because a rival acquired them, these are the exceptions to the general rule. Of the quantitative studies done on reactive proliferation, none have found a nuclear-armed rival makes a state more likely to even initiate a nuclear-weapons program, much less succeed. Furthermore, as the political scientist Jacques Hymans documents in a forthcoming book, despite the diffusion of technology, nuclear aspirants have become increasingly inefficient and unsuccessful over time.

It's therefore not surprising that in-depth case studies of Turkey's, Egypt's and Saudi Arabia's nuclear prospects have found no cause for concern. Turkey is the most capable of building nuclear weapons but already has a nuclear deterrent in the form of an estimated ninety nuclear warheads hosted on its territory for the United States. This is far more than what it is capable of producing indigenously. Additionally, it's hard to square Turkey's supposed nuclear ambitions with the recent removal of its entire stockpile of highly enriched uranium.

Egypt is far less capable of building a bomb than Turkey. Indeed, it already had a dysfunctional nuclear program during the 1960s that was abandoned despite Israel, its archenemy at the time, acquiring a nuclear capability. Even before the onset of the Arab Spring, proliferation analyst Jim Walsh argued it was "not likely that Egypt will seek, let alone acquire, nuclear weapons." In the aftermath of Mubarak's overthrow, any government in Cairo will be preoccupied with improving the lot of its people, lest it too wind up on trial. Achieving economic growth will require sustained access to foreign capital, markets and financial assistance, none of which would be forthcoming if Cairo initiated a nuclear-weapons program.