The Dangers of a Nuclear Iran: The Limits of Containment

Given Israel's status as an assumed but undeclared nuclear weapons state, the most immediate consequence of Iran's crossing the nuclear threshold would be the emergence of an unstable bipolar nuclear competition in the Middle East. Given Israel's enormous quantitative and qualitative advantage in nuclear weapons -- its arsenal is estimated to consist of anywhere from 100 to more than 200 warheads, possibly including thermonuclear weapons -- Tehran might fear a disarming preventive or preemptive strike. During a crisis, then, the Iranian leadership might face a "use them or lose them" dilemma with respect to its nuclear weapons and resolve it by attacking first. For their part, Israeli leaders might also be willing to strike first, despite the enormous risks. Israel's small size means that even a few nuclear detonations on its soil would be devastating; Iran's former president Ali Akbar Hashemi Rafsanjani was exaggerating only slightly when he claimed that "even one nuclear bomb inside Israel will destroy everything." Iran's nuclear arsenal is likely to be small at first and perhaps vulnerable to a preventive attack. Moreover, even if current and future Israeli missile defenses could not stop a full-scale premeditated attack by ballistic missiles, they might be effective against any retaliation Iran might launch if it were hit first. And the willingness to execute a preventive or preemptive strike when confronting a serious threat is a deeply ingrained element of Israel's strategic culture, as Israel demonstrated in its attacks against Egypt in 1956 and 1967, against Iraq's nuclear program in 1981, and against a suspected Syrian nuclear site in 2007. On the one occasion that Israel absorbed the first blow, in 1973, it came perilously close to defeat. In short, the early stages of an Iranian-Israeli nuclear competition would be unstable.

There is, however, at least one state that could receive significant outside support: Saudi Arabia. And if it did, proliferation could accelerate throughout the region. Iran and Saudi Arabia have long been geopolitical and ideological rivals. Riyadh would face tremendous pressure to respond in some form to a nuclear-armed Iran, not only to deter Iranian coercion and subversion but also to preserve its sense that Saudi Arabia is the leading nation in the Muslim world. The Saudi government is already pursuing a nuclear power capability, which could be the first step along a slow road to nuclear weapons development. And concerns persist that it might be able to accelerate its progress by exploiting its close ties to Pakistan. During the 1980s, in response to the use of missiles during the Iran-Iraq War and their growing proliferation throughout the region, Saudi Arabia acquired several dozen CSS-2 intermediate-range ballistic missiles from China. The Pakistani government reportedly brokered the deal, and it may have also offered to sell Saudi Arabia nuclear warheads for the CSS-2s, which are not accurate enough to deliver conventional warheads effectively. There are still rumors that Riyadh and Islamabad have had discussions involving nuclear weapons, nuclear technology, or security guarantees. This "Islamabad option" could develop in one of several different ways. Pakistan could sell operational nuclear weapons and delivery systems to Saudi Arabia, or it could provide the Saudis with the infrastructure, material, and technical support they need to produce nuclear weapons themselves within a matter of years, as opposed to a decade or longer. Not only has Pakistan provided such support in the past, but it is currently building two more heavy-water reactors for plutonium production and a second chemical reprocessing facility to extract plutonium from spent nuclear fuel. In other words, it might accumulate more fissile material than it needs to maintain even a substantially expanded arsenal of its own.

Were Saudi Arabia to acquire nuclear weapons, the Middle East would count three nuclear-armed states, and perhaps more before long. It is unclear how such an n-player competition would unfold because most analyses of nuclear deterrence are based on the U.S.-Soviet rivalry during the Cold War. It seems likely, however, that the interaction among three or more nuclear-armed powers would be more prone to miscalculation and escalation than a bipolar competition. During the Cold War, the United States and the Soviet Union only needed to concern themselves with an attack from the other. Multipolar systems are generally considered to be less stable than bipolar systems because coalitions can shift quickly, upsetting the balance of power and creating incentives for an attack.

Most existing nuclear powers have taken steps to protect their nuclear weapons from unauthorized use: from closely screening key personnel to developing technical safety measures, such as permissive action links, which require special codes before the weapons can be armed. Yet there is no guarantee that emerging nuclear powers would be willing or able to implement these measures, creating a significant risk that their governments might lose control over the weapons or nuclear material and that nonstate actors could gain access to these items. Some states might seek to mitigate threats to their nuclear arsenals; for instance, they might hide their weapons. In that case, however, a single intelligence compromise could leave their weapons vulnerable to attack or theft.