For many years, Israel has been under pressure to abandon its policy of nuclear ambiguity, and to join the Nonproliferation Treaty as a non-nuclear power. Now, Jerusalem has rejected a US-backed resolution by the UN to participate in a 2012 conference on establishing a nuclear-free zone in the Middle East. Prime Minister Binyamin Netanyahu was correct to reject these latest calls for denuclearization, especially as the world body continues to effectively ignore steady nuclear progress in Iran. The latest UN sanctions will accomplish nothing.Iran, after all, is plainly violating its binding obligations under the NPT.What is not clear, however, is that maintaining nuclear ambiguity would also be in Israel’s own interests. Ironically, from the standpoint of nuclear deterrence, there are now very good reasons to doubt that Israel should keep its bomb in the “basement.” It needs nuclear weapons. This is incontestable.Without them, it would be unable to survive in a world where existing regional foes will soon be joined by a new Arab enemy state of “Palestine” and a newly-nuclear Iran. Yet, though generally unrecognized, Israel’s security could actually be enhanced by heeding calls for an end to nuclear ambiguity.ALTHOUGH THE motives behind such calls are hypocritical and malicious at best, a selective end to nuclear ambiguity could still improve its deterrence posture. The probability of assorted enemy attacks in the future is apt to be reduced by making available certain additional information concerning Israeli nuclear weapons.Arguably, nuclear opacity has “worked” thus far. While nuclear ambiguity has done little to deter “ordinary” conventional enemy aggressions, or multiple acts of terror, it has succeeded in keeping the country’s enemies from mounting existential aggressions. Notably, these aggressions could have been mounted without nuclear or biological weapons, simply because, as the strategic theorist Carl von Clausewitz observed, there comes a tipping point when “mass counts.” Israel is half the size of Lake Michigan. Its enemies have always had an obvious advantage in “mass.” Now, excluding non-Arab Pakistan, none of Israel’s jihadist enemies has “the bomb,” but together, in a determined collaboration, they still could have acquired the capacity to carry out lethal assaults.Acting collectively, these states and their insurgent proxies, even without nuclear weapons, could already have inflicted intolerable harms upon the Jewish state. In calling for an end to Israel’s deliberate ambiguity, its foes could be doing it a huge favor. The policy of undeclared nuclear capacity will not work indefinitely. To be deterred, for example, a nuclear Iran would need assurance that Israel’s own nuclear weapons were both invulnerable and penetration-capable. Any Iranian judgments about Israel’s willingness to retaliate with nuclear weapons would therefore depend upon some prior knowledge of these weapons.Iranian perceptions of only mega-destructive Israeli nuclear weapons could undermine the credibility of its indispensable deterrent. In fact, its credibility could vary inversely with the perceived destructiveness of its nuclear arms.Although counterintuitive, in coexisting with an already-nuclear Iran,Israel would likely benefit not from any increased nuclear secrecy, butrather from expanded nuclear disclosure. In essence, this would mean afull or partial end to the bomb in the basement.Iran might decide to share some of its nuclear components and materialswith Hizbullah or another kindred terrorist group. To prevent this,Jerusalem would need to convince Iran that it possesses a range ofdistinctly usable nuclear options. Once again, nuclear ambiguity mightnot remain sufficiently persuasive to maintain its nuclear deterrenceposture.What will soon need to be calculated vis-à-vis a prospectively nuclearIran is the exact extent of subtlety with which Israel shouldcommunicate portions of its nuclear positions, intentions andcapabilities.Once faced with a nuclear fait accompli in Teheran, it would need toconvince its now principal enemy that it possesses both the will andthe capacity to make any intended nuclear aggression more costly thangainful. Here, however, no move from ambiguity to disclosure would helpin the case of an irrational nuclear enemy. For dealing with theseenemies, even preemption (anticipatory self-defense in law) could betoo late.To the extent that an Iranian leadership might subscribe to visions ofa Shi’ite apocalypse, it could cast aside all rational behavior. Werethis to happen, Iran could effectively become a nuclear suicide-bomberin macrocosm. Such a destabilizing prospect is improbable, but it isnot inconceivable. This is rapidly becoming a deeply serious prospectin already-nuclear Pakistan.To protect itself against military strikes from rational enemies,particularly attacks that could carry existential costs, Israel mustcorrectly exploit every aspect and function of its still-opaque nucleararsenal. Here, the success of its efforts would depend not only uponits selected nuclear targeting doctrine (enemy cities or militaryforces), but also upon the extent to which this choice is made known inadvance. Before such enemies can be deterred from launching firststrikes, and before they can be deterred from launching retaliatoryattacks following any non-nuclear preemption, it will not be enough toknow that Israel has The Bomb. These enemies would also need torecognize that its nuclear weapons are sufficiently invulnerable tosuch attacks, and that some are pointed directly at high-valuepopulation targets. Removing the bomb from the basement could enhance Israel’s strategicdeterrence to the extent that it would heighten rational enemyperceptions of secure and capable nuclear forces. Such a calculated endto deliberate ambiguity could also underscore its willingness to usethese nuclear forces in reprisal for certain enemy first-strike andretaliatory attacks.The UN and US President Barack Obama want Israel to end its nuclearambiguity. Fine. The moment that Iran is discovered to be close tocompleting its own nuclear weapons capability, the Jewish state shouldpromptly and purposefully remove its bomb from the basement. No countrythat simply wishes to survive could do otherwise.The writer is the author of many major books and articles on nuclear strategy and nuclear war.