I have no doubt that Iran is truly committed to Israel’s destruction and that it is willing to devote—is devoting—considerable resources to this end. But what price is Iran really willing to pay? A thousand dead—sure; a few thousand—yup; 10,000, maybe? But where does it stop? Israel is widely considered to be a nuclear power. Is Iran willing to risk a Tel Aviv-for-Tehran exchange? And who said that it will end there? (I could think of some other attractive targets, beginning with Qom.) Are they willing to risks millions, tens of millions?

I doubt it very highly. But because I could be wrong, I do believe that Israel has to consider the threat existential, even if it probably is not. The true danger in my eyes is not the “out of the blue,” erase-Israel-and-rejoice scenario, but in the influence a nuclear capability would provide Iran in lesser scenarios. For example, what happens when the next round with Hezbollah breaks out (note the intentional usage “when,” not “if”), in which the Syrians too might be tempted to join the “fun”? Suppose that Iran then decides to take advantage of this to “out” its nukes, even implicitly? With nukes, we are talking an entirely different ballgame.

Should Iran indeed go nuclear, there are a number of potential responses. (The following draws heavily a lengthy study [here] I recently prepared on aspects of the issue.)

Unilateral U.S. deterrence of Iran. This would involve a clear declaratory policy, stating that the use, or threat of use, of nuclear weapons against Israel (or alternatively, any state in the region), would be viewed as a threat against the United States itself and that it would respond devastatingly. Most countries in the region, Iran included, already believe that Israel enjoys a de facto American security guarantee. A declaratory commitment of this sort would thus not be viewed as a dramatic new step, especially following President Bush’s repeated, if somewhat less explicit, statements. Many Israelis, too, presume the existence of a de facto American commitment and it is not clear that a further verbal expression of this will meaningfully ease their threat perception.

Deterrence, nonetheless, remains a primary option. A good case can be made that Israel’s own strategic capabilities, both offensive and defensive (Arrow anti-missile system), when further buttressed by U.S. “extended deterrence,” would be a sufficient response to the Iranian threat. To refute this approach would require imputing irrationality to Iranian behavior, or at a minimum, severe miscalculation. The fact that the Iranian regime is “probably” rational, however, will not fully assuage Israel’s fears, when its very existence is at stake. The possibility that Iranian “rationality” is different, and that otherwise “unacceptable” consequences might be acceptable for its theological regime, is at the very heart of both American and Israeli fears.

Direct U.S. security guarantees for Israel. This is, in effect, what Charles Krauthammer calls the “Holocaust Declaration”—a formal US commitment. Assuming U.S. willingness to provide such a commitment—a significant “if”—Iran would know that in threatening Israel, it would be taking on the United States as well and thus face “assured destruction,” above and beyond Israel’s own capabilities. This might seem to be a “no-brainer” for Israel. Nevertheless, for reasons deeply entrenched in Israel’s national security thinking, it is likely that it would be quite reluctant to go this route:

• Israel would fear that its freedom of action would be greatly reduced, whether in regard to threats directly pertaining to Iran, or beyond.
• Israel might be concerned that the United States would demand that it divulge its independent strategic capabilities and possibly even dismantle them.
• Like the NATO allies during the Cold War, Israel would fear that the United States might not live up to its commitments, when the crunch came.

In reality, Israel has long consulted with the United States on virtually all strategic matters, including Iran, and has made few decisions of consequence in recent decades without first doing so. Moreover, Israel’s deep-seated fear of a loss of freedom of maneuver could, as in previous U.S. defense agreements (e.g. the Polaris Agreement with Britain in 1962), be addressed through an exemption from the commitment to joint consultation in cases of “supreme national interest.” Furthermore, the guarantee could be limited solely to existential dangers.

The possibility that the United States might demand that Israel divulge and even dismantle its purported nuclear option cannot be dismissed. For Israel, this would likely be a “show stopper” and it might prefer to go it alone. In truth, the United States may actually have an interest in Israel’s retaining its independent capabilities, which greatly reduce the prospects of its ever actually being called upon to invoke the guarantee. Furthermore, the whole point of the guarantee would be to strengthen Israel’s sense of security, dissuade it from independent military action and increase its willingness to “live” with a nuclear Iran. Demanding that Israel forego its ultimate capabilities would hardly be a way to achieve this.

A multilateral guarantee. If Israel might be hesitant to place its fate in a bilateral security agreement with the United States, it will certainly be loath to do so with an alliance of twenty-six nations. Additional multilateral guarantees for Israel (or all states in the region facing a nuclear threat), might include a joint U.S.-Russian one, or a collective guarantee of the P5. As in the case of NATO, Israel would be most reluctant to place its faith in multilateral agreements.

A regional security system. A further option is for the United States to establish a regional security system, in which it provides either a general guarantee to countries in the region, or a more narrowly defined one, limited to nuclear/WMD attack. This has the benefit of adding a stabilizing element to the region as a whole, and of alleviating Arab anger over what would otherwise be a one-sided commitment to Israel. The very breadth of the arrangement, however, is also its primary drawback. It is highly questionable how many of the countries in the region would join such an arrangement.

Ending Israel’s nuclear ambiguity. This is obviously one of the possible responses. The question, however, is whether this would make a significant contribution to Israeli deterrence in the face of an imminent, or declared, Iranian nuclear capability. Removing any lingering doubts regarding Israel’s nuclear status, especially if it was thought that Israel had a second-strike capability, would presumably add some measure of clarity and thus of deterrence. In fact, however, Iran must take into account that Israel is already thought to possess a nuclear arsenal, so the added utility of an end to ambiguity would appear to be marginal. The question is whether this marginal increase in deterrent value, in itself, or as part of a broader package, would justify the costs.

Regime change. The idea of regime change, as a basis for living with a nuclear Iran, has been raised for years, the assumption being that a nuclear capability in the hands of a more moderate regime would not pose an unacceptable danger. Twenty-nine years after the establishment of the Islamic Republic, however, no one has as yet devised a practical strategy for regime change. Moreover, there is no guarantee that a future regime will, indeed, be more moderate. Most importantly, in the race between the two competing timelines, regime change and an operational nuclear capability, it appears likely that the latter will win hands-down.

Chuck Freilich is a member of MESH.

The prospect of Iranian nuclear weapons therefore raises the question of an American nuclear guarantee to these Arab countries, for which the precedent is the American Cold War-era nuclear guarantee to its NATO allies in Western Europe, most of which—Germany most notably—lacked nuclear weapons of their own. There are (at least) two major differences between American nuclear deterrence in Europe during the Cold War and prospective twenty-first-century nuclear deterrence in the Persian Gulf: one makes Middle Eastern deterrence easier than was the case in Europe, the other renders it more difficult.

In the first case, the country being deterred—the Soviet Union—had, from the mid-1960s if not before, the capacity for a nuclear strike against the continental United States. This called into question the credibility of the American commitment to Western Europe. Would the United States, it was asked at the time, risk New York in order to save Paris? Charles de Gaulle, for one, publicly doubted that the United States would do any such thing, which served as part of the rationale for creating an independent French nuclear arsenal. The United States devoted a good deal of time, money, and political capital to persuading one and all that, for strategic purposes, Western Europe and North America were inextricably “coupled” and that the United States would indeed respond forcefully to a Soviet attack on Europe despite the danger this would pose to the American homeland.

Iran is presumably far from acquiring missiles of the range to strike North America, so the specter of “decoupling” would not loom over an American nuclear guarantee to the countries of the Persian Gulf. Tehran could more readily hit Western Europe, so the United States would be in the business of deterring an Iranian attack on its Cold War allies, as well; but that would simply enhance the value of the American immunity from a direct Iranian nuclear strike.

If geography makes the extension of the American nuclear umbrella to the Middle East easier than was the case for Western Europe, however, politics makes such a policy more difficult. In Europe the United States was protecting stable, like-minded democracies. The countries that would need protection in the Middle East obviously do not fit this description. The domestic character of America’s Cold War allies was particularly important because the United States stationed troops within their borders, in order to reinforce the credibility of the nuclear commitment to them as well as to defend against a non-nuclear attack by the armies of the Communist Warsaw Pact countries. The troops were, on the whole, welcome and their presence caused relatively little friction (although not none at all) between America and Europe.

Given the character of the societies against which the United States would be attempting to deter an attack in the Middle East, a smooth reception for American armed forces in large numbers on their territories could scarcely be guaranteed. The question of what additional regional military deployments, if any, would accompany an American nuclear guarantee to the Persian Gulf countries would therefore have a great deal to do with the long-term viability of such a guarantee.

Michael Mandelbaum is a member of MESH.

American extended deterrence to prevent the spread of nuclear weapons in the Middle East is not a credible policy. Conventional extended deterrence failed in the past and nuclear extended deterrence is less likely to have an impact in an area where countries do not trust the guarantees of outsiders. The French rationale for not relying on an American nuclear umbrella and leaving NATO in the 1960s is compelling. In case Iran is also successful in its project to develop inter-continental missiles, Arab leaders will inevitably ask: Why should the Americans endanger an American city for an Arab one? It is unlikely that Arab leaders will trust an American offer for a nuclear umbrella.

Offering Israel American extended deterrence is even more futile. Iranian leadership believes that the decadent and feeble Christian world (this is how the West is seen by the Ayatollahs) is ready to sacrifice the Jewish state in order to achieve a truce with the rising Muslim world. Thus, any American threats to prevent a nuclear attack on Israel will not be taken seriously in Teheran.

If Iran is allowed to become nuclear, inevitably states such as Egypt, Saudi Arabia, and Turkey will follow suit. Then, the primary challenge will be how to stabilize a nuclear multipolar Middle East. Achieving stable deterrence between Israel and Iran is a secondary concern.

Erecting stable nuclear deterrence in a Middle East with four to six nuclear powers is extremely problematic. Waltzian nonchalant attitude à la “the more the better” is the embodiment of intellectual irresponsibility. The small distances in the Middle East, the lack of adequate early warning systems, the initial rudimentary stage of nuclear arsenals, the presence of elites only newly initiated to the intricacies of nuclear strategy, the regional rules of game that allow brinkmanship and use of force, and the low sensitivity to cost, all create a strategic nightmare.

The same problems exist for a dyad relationship when Israel is part of this scenario. Many overlook the fact that the establishment of a credible second strike is a complex process fraught with uncertainties. It is an interactive process that demands continuous intellectual, scientific and financial investments.

Moreover, dictatorships with nuclear arsenals in the region may face domestic instability, which may lead to the rise of radical regimes in charge of nukes even for short periods. Unfortunately, the region displays fanatics that put Ahmedinejad in a positive light.

The claim that a balance of terror already exists because of the existence of chemical weapons is very misleading. First, there is a huge difference in lethality between nuclear and chemical weapons. Second, the existence of such arsenals has not prevented use of violence by Syria or Iraq against Israel. Emulating the balance of terror between the two superpowers is not self evident.

As it is very unlikely to stop Iran becoming nuclear by diplomacy and/or economic sanctions, it is only military action that can prevent the descent of the Greater Middle East into a very brutish region.

Efraim Inbar is professor of political studies at Bar-Ilan University and director of the Begin-Sadat (BESA) Center for Strategic Studies.