Excruciating But Indispensable: Calculating Probabilities of an Israel-Iran Nuclear War

Prof. Louis René Beres

Credo quia absurdum, “I believe because it is absurd.”-Tertullian

By definition, an Israel-Iran nuclear exchange is presently impossible. Though Iran is vigorously pursuing a military nuclear capability, it still has a substantial way to go before it can claim competitive nuclear power status. Correspondingly, prudent survival preparations for Israel should take a variety of complex and intersecting forms. Israel’s leaders already understand that (1) nothing short of a massive non-nuclear preemption could summarily stop Tehran’s nuclearization (a nuclear preemption is essentially inconceivable), and (2) if such a defensive first-strike could meet the authoritative tests of “anticipatory self-defense” under international law, it’s overall result would still be catastrophic.

                What next for Jerusalem/Tel Aviv? Above all, Israeli strategists should examine the country’s presumptively available security options as an intellectual rather than political task. This imperative remains, prima facie, an overriding and unchanging strategic obligation.

               There is more. This cautionary conclusion about planning is compelling because any tactically successful conventional preemption against Iranian weapons and infrastructures would come at more-or-less unacceptable costs. Already, in 2003, when this writer’s Project Daniel Group presented an early report on Iranian nuclearization to then-Israeli PM Ariel Sharon, prospective Iranian targets were more directly threatening to Israel than had been Iraq’s nuclear Osiraq reactor back on June 7, 1981.

               To the limited extent that they could be suitably estimated, the plausible risks of an Israel-Iran nuclear war would ultimately depend upon whether such a conflict was intentional, unintentional, or accidental. Apart from applying this critical three-part distinction to their analysis, there could be no good reason to expect any usefully systematic strategic assessments emerging from Tel Aviv (MOD/IDF). Once applied, however, Israeli planners should understand that their complex subject is without any useful precedent.

This uniqueness represents a quality of critical predictive importance.  The peremptory rules of logic and mathematics preclude any meaningful assignments of probability in matters that are unprecedented or sui generis. To come up with any meaningful estimations of probability, these predictions would have to be based upon the determinable frequency of relevant past events. Unassailably, there have been no such events. Incontestably, there have been no nuclear wars.

               Still, it is essential that competent Israeli strategic analysts do their best to examine all current and future nuclear risks from Iran. To some ascertainable extent, it may be sensible for them to study what is happening between Washington and Pyongyang as a “model” for calculating Israel’s long-term nuclear perils.  Looking back, in examining the overheated rhetoric that had emerged from US President Donald J. Trump and North Korean President Kim Jung-Un, neither leader was paying sufficiently close attention to the manifestly grave risks of an unintentional or accidental nuclear war.

Among other things, this means that both Trump and Kim seemed to assume the other leader’s decisional rationality and also the mutual primacy of decisional intention. If no such assumption had existed, it would have made no sense for either president to deliberately strike existential retaliatory fear in the heart of the other. What are the lessons here for Israel vis-à-vis Iran? Should Israel similarly assume a fully rational adversary in Iran? To be sure, any such assumption would be more or less reassuring in Jerusalem, but (far more importantly) would it also be correct?

               During his dissembling tenure, Donald J. Trump, then US president, openly praised feigned irrationality as a tangible US security strategy. But such a preference could never be “actionable” without incurring assorted dangers, for America or for Israel. Although neither Israel nor Iran might actually want a war, either or both “players” could still commit grievous errors during competitive searches for “escalation dominance.” The only predictable element here would be the dense scenario’s inherent unpredictability, especially if world system governance continues its tilt from traditional anarchy to chaos.

               There is more. An unintentional or inadvertent nuclear war between Israel and Iran could take place not only as the result of misunderstandings or miscalculations between fully rational leaders, but also as the unintended consequence of mechanical, electrical, or computer malfunctions. This includes hacking interference, and should bring to mind a corollary distinction between unintentional/inadvertent nuclear war and an accidental nuclear war. Though all accidental nuclear war must be unintentional, not every unintentional nuclear war would be generated by accident. An unintentional or inadvertent nuclear war could sometime be the result of misjudgments (both fundamental and seemingly trivial) about enemy intentions.

               “In war,” says Prussian strategist Carl von Clausewitz famously in his classic On War, “everything is simple, but the simplest thing is difficult.” In fashioning a successful “endgame” to any future nuclear confrontation with Iran, it would be vital for Israel’s leaders to understand that this sort of crisis is about much more than maximizing any “correlation of forces” or missile-interception capabilities. It will be about imaginative intuition and variously antecedent notions of dialectical thinking.

               There are many complex details. As a nuclear war has never been fought, what will be needed in Jerusalem/Tel Aviv is more broadly intellectual guidance than Israel could ever reasonably expect from even its most senior military officers. In essence, ipso facto, there are no recognizable experts on fighting a nuclear war, not in Jerusalem, not in Tehran, not anywhere.  It was not by accident that the first capable theoreticians of nuclear war and nuclear deterrence in the 1950s were academic mathematicians, physicists and political scientists.

               There remains one last point about any still-estimable risks of an Israel-Iran nuclear war. From the standpoint of Jerusalem, the only truly successful outcome could be a crisis or confrontation that ends with a reduction of Iranian nuclear war fighting capabilities andintentions. It would represent a serious mistake for Israel to settle for any bloated boasts of “victory” that are based only upon a one-time avoidance of nuclear war. Israel ought never to be taking existential risks with Iran if the best anticipated outcome could only be status quo ante bellum.

               Providing for Israeli national security vis-à-vis a still-nuclearizing Iran ought never to be a visceral or “seat-of-the-pants” obligation. Without any suitably long-term, systematic and thoughtful plan for avoiding a nuclear war with the Islamic Republic in Tehran, a no-holds-barred military conflict could sometime ensue. To prepare optimally for such a more-or-less-unexpected conflict, Israel should remain focused on stable nuclear deterrence, a condition requiring continuously refined analytic distinctions between deliberate, inadvertent and accidental nuclear war. On this essential focus, the greatest dangers will lie in fostering outcomes that neither party would actually favor.

               Credo quia absurdum, says the ancient philosopher Tertullian. “I believe because it is absurd.”

Louis Rene Beres was educated at Princeton (Ph.D., 1971) and is the author of many books and articles dealing with nuclear strategy and world order reform. Dr. Beres, Professor Emeritus of International Law at Purdue, publishes at The New York Times; The Atlantic; Jewish Business News; Harvard National Security Journal (Harvard Law School); JURIST; Bulletin of the Atomic Scientists; Yale Global Online (Yale University); World Politics (Princeton); International Journal of Intelligence and Counterintelligence; Infinity Journal (Tel Aviv); BESA Perspectives (Israel); INSS Strategic Assessment (Tel Aviv); Modern War Institute (West Point); The War Room (Pentagon); Parameters: Journal of the US Army War College (Pentagon); Armed Forces and Society; global-e (University of California); Special Warfare (Pentagon); Horasis (Switzerland); Modern Diplomacy; JURIST; Brown Journal of World Affairs (Brown University); International Security (Harvard); Air-Space Operations Review (USAF); American Political Science Review; American Journal of International Law; Strategy Bridge; Strategic Review; and Middle East Review of International Affairs.

This article was first published in Modern Diplomacy.