“It is in the thick of a calamity,” writes Albert Camus in The Plague, “that one gets hardened to the truth, in other words, to silence.” Whether we like it or not, “silence” is what we shall soon come to expect regarding Iran. Depending upon Israel’s precise eleventh-hour strategic decisions, it shall be a silence of protracted coexistence, or, more ominously, a quiet of catastrophic destruction.In fashioning these unavoidable decisions, Israel’s leaders, civilian and military, will have to make critical antecedent judgments concerning Iranian rationality. What will they believe? Will their counterparts in Tehran value Iran’s physical survival more highly than any other preference, or combination of preferences? If so, some system of stable nuclear deterrence might still be expected in Jerusalem. If not, Prime Minister Binyamin Netanyahu and his senior advisors will have to immediately begin identifying promising and creative ways of deterring a new nuclear enemy. This wager will presumably be calculated on Iran's unique ordering of preferences. Even when dealing with an irrational adversary, one which does not make national survival its top priority, there is still the possibility that the country maintains a distinct and determinable hierarchy of preferences. In the case of now-nuclearizing Iran, such a hierarchy would likely be highlighted by certain readily identifiable religious values and institutions. For example, a credible Israeli retaliatory threat to destroy certain Iranian holy cities, or landmarks, or individual persons, could still “work.”Deterrence of an already-nuclear Iran would become useless only where that country’s leadership is neither rational nor irrational, but mad. In such residual – but assuredly still possible – circumstances, Israel’s only remaining hope would lie in some very late attempt at preemption, an effort that would carry stupendous strategic and political costs, or in unimaginably effective systems of anti-missile defense. Although ballistic missile defense could substantially reduce the harm of any Iranian first-strike aggression against Israel, even the very best network of active defenses would have intolerable levels of “leakage.”Israel’s primary focus should be on a measured loosening of its historic ambiguity regarding its nuclear weapon capabilities, the so-called “bomb in the basement.” This could help ensure that any prospective Iranian aggressor views Tel-Aviv’s nuclear retaliatory forces as genuinely usable. A little known irony, here, is that if an enemy perceives Israel's nuclear weaponry to be too uniformly destructive, it could actually undermine Israel’s deterrent credibility.For Israel, over the past several years, the strategic options have been plain: Strike preemptively, almost certainly without any active American collaboration, or go along with the world community’s quaint reliance upon “sanctions.” The first option, although limited to military and industrial targets, would have carried enormous political costs and security risks. The second, which has in fact been “selected,” amounted to doing nothing.Camus would have understood. The coming “plague,” could carry with it a very heavy truth. A nuclear war in the Middle East would resemble any other incurable disease. With deep and profound silence approaching in an always indifferent world, Israel now requires a refined strategic doctrine that can effectively combine deterrence, targeting, war fighting, preemption, and defense. Israel must now prepare a useful array of operations and tactics. Unless an unanticipated, sweeping regime change occurs in Tehran, the country could remain animated by jihad, specifically the Shiite visions of “apocalypse.” Israel's own nuclear strategy of survival is likely to be based on utterly realistic assumptions of enemy aggression. These assumptions will not ignore the always conceivable prospect of enemy irrationality or enemy madness. Israel must also consider the impact of a potential Palestinian state. If following strong support from US President Barack Obama or even his successor, a twenty-third Arab sovereignty is declared, “Palestine” would become an optimal platform for major international aggression. The substantial dangers posed, including nuclear war and nuclear terrorism, could affect not only Israel, but also the United States.It will always be very difficult for us to imagine nuclear weapons as anything but intrinsically evil. Still, there are circumstances where a particular state's possession of these bombs and missiles could be all that prevents catastrophic war, or even genocide. The International Court of Justice ruled in its Advisory Opinion on July 8, 1996, “The Court cannot conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defense….” where “…the very survival of a State would be at stake."Israel is not Iran. Israel does not seek redemption through any form of final battle. Israel makes no gratuitous threats of harm to others. Israel does not rattle the saber of its own nuclear capabilities. Israel, not a party to the 1968 Non Proliferation Treaty (NPT), is not in violation of any international legal agreement. Not all members of the nuclear club are a menace. Some, like Israel, represent a distinct asset to world peace. Should it ever be deprived of its presumed nuclear forces, Israel would become vulnerable to massive attacks from certain enemy states. Israel’s nuclear weapons are not the problem. In the Middle East, a far-reaching and unreconstructed Islamist commitment to remove the “Zionist entity," forms the only real core source of violence and insecurity.With nuclear weapons, and an associated nuclear strategy, Israel could deter a rational – and quite possibly an irrational – enemy’s unconventional attacks, as well as most large conventional aggressions. With such weapons, Israel could also still launch non-nuclear preemptive strikes against targets that threaten Israel's annihilation. Without these weapons, these acts of anticipatory self-defense would probably represent the onset of a wider war. In the thick of calamity, we learn from Camus, we may encounter not only silence, but also a too long delayed lucidity. Even undisclosed, Israel’s nuclear arsenal offers an indispensable impediment to any actual use of nuclear weapons. Joined with a more coherent strategic doctrine, one that would include incremental expressions of nuclear disclosure and also certain codifications of preemption and counter-city targeting, these weapons could soon represent the entire Middle East’s principal line of defense against future Iranian nuclear aggression and regional nuclear war. Louis René Beres is the author of many books and articles dealing with nuclear strategy and nuclear war. Professor of Political Science and International Law at Purdue, he lectures widely in the United States and abroad on international security and legal issues.John T. Chain was Commander-in-Chief, U.S. Strategic Air Command , and director, Joint Strategic Target Planning Staff. General Chain also served as chief of staff, Supreme Headquarters, Allied Powers Europe, and director, Bureau of Politico-Military Affairs, U.S. Department of State.