For Israel, nuclear threats extend beyond Iran. Even a favourable outcome to the current war could produce new adversarial configurations. Over time, such actors – individually or in loose alignment – could create new nuclear risk scenarios, even without acquiring nuclear weapons themselves. Concurrently, assorted jihadi terrorist groups could act as “force multiplying” surrogates of an “Iran replacement enemy.”
To prepare for such emerging or re-configuring threats, Jerusalem (and also Washington) will still need to prepare for “the worst.” A structured, analytical approach is required with “generality” serving as a guiding principle. For Israel, comprehensive theorizing should replace ad hoc or crisis-driven policy reflexes sometimes evident in U.S. President Donald Trump’s messaging.
To be sure, intra-crisis hyperbole would be gratuitous and counter-productive. The U.S.’ broad, declaratory threats of “obliteration” are not necessarily more credible than carefully calibrated deterrent messaging. It should already be plain that strategic deterrence and nuclear war avoidance are about much more than high-technology weapon systems or weapon system “lethality” (the conflict quality most loudly acclaimed by US “Secretary of War” Pete Hegseth).
It is necessary to consider specific contingencies. How might Israel find itself engaged (wittingly or unwittingly) in a nuclear war? Under what identifiable circumstances could Israel sometime have to face credible nuclear perils or actual nuclear attacks?
Plausibly, though Iran has been set back in building “a bomb,” it retains enough fissile material capacity to launch radiological or asymmetric nuclear-related contingencies. In this connection, the prospects for external actors gaining reliable control over Iran’s dispersed assets remain limited. In the final analysis, strategic deterrence (nuclear and non-nuclear) is not about superiority. Even a distinctly “weaker” enemy could inflict unacceptable retaliatory harms on Israel.
There is more. All conceivable nuclear war scenarios remain imprecise and unprecedented or sui generis. As one example, an enemy attack on Israel’s Dimona nuclear reactor could significantly increase escalation pressures, potentially including nuclear dimensions under extreme conditions. This is the case even if the attacking state were itself non-nuclear and if the attack outcome fell short of a major radiological release.
To proceed efficiently and rationally, Israel’s strategic planners will need to examine and re-examine core canons of science-based inquiry. Looking beyond the current war, four precisely delineated narratives could cover the analytic “bases” of all nuclear conflict preparedness: Nuclear Retaliation; Nuclear Counter Retaliation; Nuclear Preemption; and Nuclear War fighting. Each narrative or scenario warrants immediate and continuous study, including systematic considerations of variously possible intersections.
Nuclear retaliation
Should an enemy state ever launch a nuclear missile first-strike against Israel, Jerusalem would be expected to respond with nuclear retaliation (subject to operational feasibility and strategic doctrine.) If enemy first-strikes were to involve certain other forms of unconventional weapons, especially high-lethality biological weapons, nuclear reprisal could not be ruled out. That particular response would depend, however, on Jerusalem’s assessments of escalation risk, damage limitation, and broader strategic context.
If Israel were to absorb “only” a massive conventional attack, a nuclear retaliation could still not be ruled out per se, especially if: (a) the state aggressor(s) was perceived to hold nuclear and/or other unconventional weapons in reserve; and/or (b) Israel’s leaders were to believe that exclusively non-nuclear retaliations could not prevent annihilation of the Jewish State (i.e., a genocide). A nuclear retaliation by Israel would be highly unlikely in circumstances where enemy actions remained conventional, proportionate, and directed exclusively at military targets rather than civilian populations.
Nuclear counter-retaliation
Should Israel feel compelled to preempt enemy state aggression with conventional weapons, the target state’s response would determine Jerusalem’s next moves. If this response were in any way nuclear, Israel would expectedly turn to nuclear counter-retaliation. If this retaliation were to involve other weapons of mass destruction, Israel might then feel pressed to take seemingly appropriate escalations. Such dynamics would likely reflect perceptions of escalation control.
All relevant decisions would depend upon Jerusalem’s early judgments of enemy state intent and accompanying calculations of damage-limitation. Should the enemy state response to Israel’s preemption be limited to hard-target conventional strikes, further escalation to nuclear counter-retaliation would be unlikely. If, however, the enemy conventional retaliation was “all-out” and directed at Israeli civilian populations, an Israeli nuclear counter-retaliation could not be excluded.
It would appear that such a counter-retaliation could be ruled out only if the enemy state’s conventional retaliation was proportionate to Israel’s preemption, confined exclusively to Israeli military targets, circumscribed by the legal limits of “military necessity” (a limit routinely codified in the law of armed conflict), and accompanied by variously explicit and verifiable assurances of non-escalatory intent.
Nuclear preemption
It is implausible (at least for the foreseeable future) that Israel would decide to launch a preemptive nuclear strike. Although circumstances could conceivably arise in which such a strike would be technically rational, it is nonetheless unlikely that Israel would allow itself to reach such dire circumstances. Unless the nuclear weapons involved were used in a fashion still consistent with the codified and customary rules of war, such an action would likely raise serious legal and normative challenges under international law.
Even if such consistency were possible, the psychological/political impact on the world community would be significant, with potentially sustained international consequences. It follows that an Israeli nuclear preemption could be expected only where (a) Israel’s state enemies had acquired nuclear and/or other weapons of mass destruction judged capable of annihilating the Jewish State; (b) these enemies had made it clear that their operational military intentions paralleled their capabilities; (c) these enemies were believed ready to begin a “countdown to launch;” and (d) Jerusalem believed that Israeli non-nuclear preemptions could not possibly achieve even minimum levels of damage-limitation. Succinctly, this means levels consistent with the preservation of the Israeli state.
Nuclear warfighting
If nuclear weapons were ever introduced into actual conflict between Israel and specific enemies, either by Israel itself or an Arab/Islamic foe, nuclear warfighting dynamics could emerge at one level or another. This would be true so long as: (a) enemy first-strikes against Israel would not destroy Jerusalem’s second-strike nuclear capability; (b) enemy retaliations for an Israeli conventional preemption would not destroy Jerusalem’s nuclear counter-retaliatory capability; (c) Israeli preemptive strikes involving nuclear weapons would not destroy adversarial second-strike nuclear capabilities; and (d) Israeli retaliation for enemy conventional first-strikes would not destroy enemy nuclear counter-retaliatory capability.
Ipso facto, in order to satisfy essential survival requirements, Israel’s strategic planning would likely prioritize reducing the vulnerability of (a) and (b) while complicating adversary targeting success.
In absolutely all cases, Israel’s nuclear strategy and forces should remain oriented to deterrence, not war fighting. With this counsel in mind, Jerusalem has likely already taken steps to reject (1) tactical or relatively low-yield “battlefield” nuclear weapons, and (2) corresponding plans for counter-force targeting. For Israel, without exception, nuclear weapons are primarily relevant to deterrence, rather than post-strike retribution. Moreover, recalling Israel’s “bomb in the basement,” this calculation should become incrementally “less ambiguous.”
There is still more. These four scenarios should remind Israeli planners and decision-makers of the always-overriding need for coherent nuclear strategy and doctrine. Among other things, this need stipulates a counter-value targeted nuclear retaliatory force, one that is recognizably secure from enemy first-strikes and also capable of penetrating an enemy state’s active defenses.
Such recommended strategic calculation points in one principal direction: Israel needs to consider a theory-based end to its traditional posture of “deliberate nuclear ambiguity.” Adjustments to nuclear ambiguity – whether toward greater clarity or continued opacity – would affect deterrence perceptions. Though possibly counter-intuitive, possession of nuclear forces alone may not be sufficient to ensure credible deterrence for Israel.
In all such complex strategic planning, analytical rigour and structured reasoning remain central. Prospective aggressors, whether nuclear or non-nuclear, must be encouraged to believe that Israel has the willingness to launch a measured nuclear retaliation and that Jerusalem’s discernible nuclear forces are sufficiently invulnerable to first-strike attacks. These enemies should also be encouraged to expect that Israel’s designated nuclear forces could reliably penetrate their overlapping missile, drone, and air defenses.
The core task is to support the utility and security of Israel’s nuclear retaliatory forces. Accordingly, to maximize Israeli nuclear deterrence, this task should emphasize the survivability, resilience, and penetration capability of pertinent military forces. Under certain conditions, the credibility of Israeli nuclear deterrence could vary inversely with the destructiveness of its weapons. In the end, nuclear deterrence is not about having the “biggest button” (the self-deceiving metaphor used earlier by U.S. President Donald J. Trump vis-à-vis North Korea), but the perceived willingness to retaliate with “assured destruction.” Also vital will be the assumed rationality or irrationality of adversarial (state and sub-state) leaderships.
Finally, Israel will need to prepare differently for an expectedly rational nuclear adversary than for an irrational one. In such nuanced and bewildering circumstances, national decision-makers in Jerusalem and also Washington will have to distinguish between genuine enemy irrationality and pretended enemy irrationality. In actual practice, distinguishing between these categories would pose significant analytical and political challenges.
As Friedrich Dürrenmatt observed, “The worst does sometimes happen.”