Another computational strategic caveat unfolds. A newly-nuclear Iran, if still rational, would require incrementally increasing numbers of offensive missiles in order to achieve or maintain a sufficiently destructive first-strike capability against Israel. There could come a time, however, when Iran would be able to deploy more than a small number of nuclear-tipped missiles. Should that happen, all of Israel's active defenses, already inadequate as ultimate guarantors of physical protection, could also cease functioning as critically supportive adjuncts of Israeli nuclear deterrence.
Preemption against Iran, even at very great cost and risk to Israel, could prove indispensable in the case of Iranian decisional "madness." Yet, in itself, this destabilizing scenario is insufficiently plausible to warrant defensive first-strikes. Israel would be better served by a bifurcated or two-pronged plan for successful deterrence. Here, one "prong" would be designed for an expectedly rational Iranian adversary; the other, for a presumptively irrational one.
In broadest policy contours, we already know what Israel would need to do in order to maintain a stable deterrence posture vis-à-vis a newly-nuclear Iran. But what if the leaders of a newly-nuclear Iran did not meet the characteristic expectations of rational behavior in world politics? In short, what if this leadership, from the very start, or perhaps more slowly, over time, chose not to consistently value Iran's national survival as a state more highly than any other preference, or combination of preferences?
In such threatening circumstances, Israel's leaders would need to look closely at two eccentric and more-or-less untried nuclear deterrence strategies, possibly in tandem with one another. First, these leaders would have to understand that even an irrational Iranian leadership could display distinct preferences, and associated hierarchies of preferences. Their task, then, would be to determine precisely what these particular preferences might be (most likely, they would have to do with certain presumed religious goals), and, also, how these preferences are apt to be "ranked" in Tehran.
Second, among other things, Israel's leaders could have to determine the likely deterrence benefits of their own pretended irrationality. An irrational Iranian enemy, if it felt that Israel's decision-makers were irrational themselves, could be determinedly less likely to strike first. Years ago, Gen. Moshe Dayan, then Israel's Minister of Defense, urged: "Israel must be seen as a mad dog; too dangerous to bother." With this prophetic warning, Dayan had revealed an intuitive awareness of the possible long-term benefits to Israel of feigned irrationality.
There is a pertinent prior point. Before Israel's leaders could proceed gainfully with any plans for deterring an irrational nuclear adversary, especially Iran, they would first need to be convinced that this adversary was, in fact, genuinely irrational, and not merely pretending irrationality.
The importance of an early sequencing for this notably vital judgment cannot be overstated. Because all specific Israeli deterrence policies must be founded upon the presumed rationality or irrationality of prospective nuclear enemies, accurately determining precise enemy preferences and preference orderings will have to become the very first core phase of strategic planning in Tel-Aviv.
Finally, as a newly-nuclear Iran could sometime decide to share some of its fissile materials and technologies with assorted terrorist groups, Israel's leaders will also have to deal with the prospect of irrational nuclear enemies at the sub-state level. This daunting prospect is more likely than that of irrationality at the national or state level. At the same time, at least in principle, the harms suffered from any such instances of nuclear terror would probably be less overwhelming.