Israel's nuclear weapons, unacknowledged and undisclosed, exist only to prevent certain forms of aggression. It is inconceivable that this deterrent force would ever be used except in certain defensive operations or in reprisal for massive enemy first-strikes, especially for Arab or Iranian attacks involving biological and/or nuclear weapons. Israel's nuclear weapons will continue to reduce the risks of regional unconventional war as long as pertinent enemy states remain rational and remain convinced that Israel will retaliate accordingly when struck first.

But what if a bellicose enemy state were allowed to acquire nuclear weapons? An example would be an Iraq that successfully evades both UN inspectors and American bombs. Whether for reasons of miscalculation, outright irrationality or because of the presumed imperatives of "Jihad," such a state could opt to launch a nuclear first-strike against Israel. Israel would certainly respond, to the extent possible, with a nuclear retaliatory strike. Although nothing is publicly known about Tel-Aviv's precise targeting doctrine, such a strike might surely be launched against the aggressor's capital city or against a similarly high-value urban target. There would be no assurances, in response to this sort of aggression, that Israel would limit itself to striking back against exclusively military targets. Quite the contrary.

What if enemy first-strikes were to involve "only" chemical and/or biological weapons? Here Israel might launch a nuclear reprisal, but this would depend largely upon Israel's calculated expectations of follow-on aggression and on its associated determinations of comparative damage- limitation. Should Israel absorb a massive conventional first-strike, a nuclear retaliation could still not be ruled out altogether. This is especially the case if: (a) the aggressor were perceived to hold nuclear or other weapons of mass destruction in reserve; and/or (b) Israel's leaders were to believe that non-nuclear retaliations could not prevent national annihilation. In this connection, the threshold of existential harms would likely be far lower than wholesale physical devastation.

Faced with imminent and existential attacks, Israel - properly taking its cue from THE NATIONAL SECURITY STRATEGY OF THE UNITED STATES OF AMERICA - could decide to preempt enemy aggression with conventional forces. Announced on September 20, 2002, this new American strategy affirms the growing reasonableness of anticipatory self-defense under international law. If Israel were to draw upon such authoritative expressions of current U.S. policy, the targeted state's response would determine Israel's subsequent moves. If this response were in any way nuclear, Israel would assuredly undertake nuclear counter-retaliation. If this enemy retaliation were to involve chemical and/or biological weapons, Israel might also determine to take the escalatory initiative. This sort of initiative is known in the military profession as "escalation dominance," and could be essential, for Israel, to favorable intrawar deterrence.

If the enemy state's response to Israeli preemption were limited to hard-target conventional strikes, it is improbable that Israel would resort to nuclear counter-retaliation. On the other hand, if the enemy state's conventional retaliation were an all-out strike directed toward Israel's civilian populations as well as to Israeli military targets - an existential strike, for all intents and purposes - an Israeli nuclear counter- retaliation could not be ruled out. Such a counter-retaliation could be ruled out only if the enemy state's conventional retaliations were entirely proportionate to Israel's preemption; confined entirely to Israeli military targets; circumscribed by the legal limits of "military necessity"; and accompanied by explicit and verifiable assurances of no further escalation.

It is highly unlikely, but not inconceivable, that Israel would ever decide to preempt enemy state aggression with a nuclear defensive strike. While circumstances could surely arise where such a defensive strike would be completely rational and also completely acceptable under international law, it is improbable that Israel would ever permit itself to reach such dire circumstances. An Israeli nuclear preemption could be expected only if: (a) Israel's state enemies had acquired nuclear or other unconventional weapons presumed capable of destroying the tiny Jewish State; (b) these enemy states had made explicit that their intentions paralleled their capabilities; (c) these states were authoritatively believed ready to begin a countdown-to-launch; and (d) Israel believed that non-nuclear preemptions could not possibly achieve the minimum needed levels of damage-limitation - that is, levels consistent with national survival.

Should nuclear weapons ever be introduced into a conflict between Israel and the many countries that wish to destroy it, some form of nuclear war fighting could ensue. This would be the case so long as: (a) enemy state first-strikes against Israel would not destroy the Jewish State's second- strike nuclear capability; (b) enemy state retaliations for Israeli conventional preemption would not destroy Israel's nuclear counter- retaliatory capability; (c) Israeli preemptive strikes involving nuclear weapons would not destroy enemy state second-strike nuclear capabilities; and (d) Israeli retaliation for enemy state conventional first-strikes would not destroy enemy state nuclear counter-retaliatory capability. From the standpoint of protecting its security and survival, this means that Israel must now take proper steps to ensure the likelihood of (a) and (b) above, and the unlikelihood of (c) and (d).

Both Israeli nuclear and non-nuclear preemptions of enemy unconventional aggressions could lead to nuclear exchanges. This would depend, in part, upon the effectiveness and breadth of Israeli targeting, the surviving number of enemy nuclear weapons, and the willingness of enemy leaders to risk Israeli nuclear counter-retaliations. In any event, the likelihood of nuclear exchanges would obviously be greatest where potential Arab or Iranian aggressors were allowed to deploy ever-larger numbers of unconventional weapons without eliciting timely preemptions. The case of Iraq is glaringly apparent here.

Should such deployment be allowed to take place, Israel might effectively forfeit the non-nuclear preemption option. Here its only alternatives to nuclear preemption could be a no-longer viable conventional preemption or simply waiting to be attacked itself. It follows that the risks of an Israeli nuclear preemption, of nuclear exchanges with an enemy state, AND of enemy nuclear first-strikes could all be reduced by timely Israeli non-nuclear preemptions. These preemptions would be directed at critical military targets and/or at pertinent regimes. The latter option could include dedicated elimination of enemy leadership elites.

Nuclear war is like any other incurable disease. The only remedies lie in prevention. Looking at the volatile Middle East, where several Arab states and possibly Iran are still sworn to "root out the Zionist cancer," the most promising remedy is to ensure that Israel remain the only regional nuclear power. To this end, Israel must now be permitted to do whatever is needed to successfully prevent and deter enemy aggression.