Oddly enough, with events spiraling out of control in Syria, no one is paying much attention to the puppet master: Iran. As a result, Tehran manages to proceed unhindered with its development of nuclear weapons. In a few years, the strategic shortsightedness of both Washington and Jerusalem could become explosively apparent.What will happen next? Inevitably, the United States and Israel, more or less cooperatively, will seek a dependable regional system of nuclear deterrence. But could such a last ditch security effort succeed?Before it can work, any system of deterrence must be based on an assumption of rationality. This means that each side must believe the other will value its continued national survival more highly than any other preference, or combination of preferences.LOUIS RENÉ BERES was educated at Princeton (Ph.D., 1971), and is Professor of International Law at Purdue. Born in Zurich, Switzerland, on August 31, 1945, he is the author of many major books and articles dealing with nuclear strategy and nuclear war. His most recent publication dealing with Syria, Israel, and the law of war, appears in the Harvard National Security Journal, Harvard Law School (August, 2013). Ten years earlier, in Israel, Professor Beres served as Chair of Project Daniel (2003). He is a frequent contributor to The Jerusalem Post.To be sure, it is at least possible that pertinent decision-makers in Tehran would be rational. Still, it is entirely plausible that, at some point, this core assumption would no longer remain valid. Moreover, even a fully rational Iranian adversary could sometime decide to launch against Israel, because of: (1) incorrect information used in its vital decisional calculations; (2) mechanical, electronic, or computer malfunctions; (3) unauthorized decisions to fire, in the national decisional command authority; or (4) coup d'état.Probably, in the aftermath of an Iranian nuclear attack upon Israel, the Jewish State would not disappear. Should this be taken as "reassuring?" After all, and at a minimum, tens of thousands of Israelis, Arabs as well as Jews, would be crushed, torn apart, and severely burned.Large numbers would fall victim to raging firestorms. Fallout injuries would include whole-body radiation injury, produced by penetrating, hard gamma radiations; superficial radiation burns, produced by soft radiations; and assorted injuries produced by deposits of radioactive substances within the body.After an Iranian nuclear attack, even a "small" one, those few medical facilities that might still exist in Israel would be taxed beyond capacity. Water supplies would quickly become unusable. Housing and shelter could be unavailable for hundreds of thousands (in principle, at least, perhaps even millions) of survivors. Transportation would break down to rudimentary levels. Food shortages would be crippling, critical, and forseeably, very long-term. All normal mechanisms of economic exchange would be shattered. Emergency police and fire services would be decimated. Most systems dependent upon electrical power could stop functioning, perhaps for months, or even longer. Severe trauma would produce widespread disorientation and psychiatric disorders, pathologies for which there would be no available therapeutic services.After an Iranian nuclear attack, many Israeli survivors could expect an increase in serious and degenerative pathologies. They could also expect premature death, impaired vision, and sterility. Following what we know about atomic bomb effects upon Hiroshima and Nagasaki, an increased incidence of leukemia and cancers of the lung, stomach, breast, ovary and uterine cervix would be indicated.Extensive fallout would leave its mark upon Israel. Over time, it would upset many delicately balanced relationships in nature. Those Israelis who had survived the nuclear attack would still have to deal with enlarged insect populations. Like the locusts of biblical times, mushrooming insect hordes could spread widely beyond the radiation-damaged areas in which they first arose.Insects are generally more resistant to radiation than humans. This fact, coupled with the prevalence of unburied corpses, uncontrolled waste, and untreated sewage, would generate tens of trillions of flies and mosquitoes. Breeding in the dead bodies, these insects would make it utterly impossible to control typhus, malaria, dengue fever, and encephalitis. Throughout Israel, tens or even hundreds of thousands of rotting human corpses would pose the single largest health threat. Simply to bury the bodies would prove to be a staggering and conceivably impossible task. Then, unceremonious mass cremations could prove to be the only viable "final solution."These same catastrophic effects, possibly even more expansive and destructive, could be wreaked upon Iran by Israel. With near absolute certainty, an immediate Israeli nuclear retaliation for any Iranian nuclear aggression would be initiated. In both Israel and Iran, legions of battered survivors would envy the dead.None of this strategic scenario would need to be considered if Iran could still be kept distant from nuclear weapons. Barring the very unlikely prospect of an eleventh-hour preemption against Iranian hard targets, however, it will become necessary to implement a broadly stable program for regional nuclear deterrence. Within this historically familiar threat system, Israel might still be able to identify certain remaining deterrence options.These options would pertain to both rational and irrational decision-makers in Tehran. By definition, irrational Iranian adversaries would not value their own national survival most highly. Nonetheless, they could still maintain a determinable and potentially manipulable ordering of preferences. Washington and Jerusalem, therefore, should promptly undertake a meticulous effort (1) to adequately anticipate this prospective ordering; and (2) to fashion deterrent threats accordingly.Future Iranian preference-orderings would not be created in a vacuum. Among other things, assorted strategic developments in already-nuclear Pakistan, and (eventually) "Palestine," could impact such orderings. This impact could manifest itself in the form of certain game-changing "synergies," or, in more narrowly military parlance, as significant "force multipliers."The preference orderings of a nuclearizing Iran will be effected, especially in the short term, by whatever happens to Tehran's surrogate in Damascus. If an American missile strike is launched against certain hard targets of the Assad regime, US President Barack Obama may, however unintentionally, also be declaring a de facto war against Iran.In such increasingly likely circumstances, Washington's jurisprudential motives would not include a wider conflict, but these high-sounding presidential motives could prove irrelevant. Here, Tehran would almost certainly choose to accelerate the pace of its nuclear weapons program. In part, this acceleration would represent the result of an increased fear of becoming the object of an American and/or Israeli preemptive attack itself.Over time, Iran's cumulative response to any impending American attacks on Syrian regime targets could trigger a reduced willingness to abide by the logic of deterrence. It follows that any such American attacks, especially if they did not remain expectedly "tailored" or "limited," could actually hasten the outbreak of a more-or-less region-wide war, ultimately involving nuclear arms. This is not to suggest that a suitably proportionate American military response to Syrian regime crimes against humanity would be inherently law-violating or "wrong," but only that there might also be various unintended yet grievously substantial nuclear consequences.