Nuclear Israel
Nuclear IsraeliStock

Introduction: In the closing days of 2023, Israeli Prime Minister Benjamin Netanyahu advised his nation that Operation Swords of Iron would take additional months to complete. During this period of extended Israeli involvement with counter-terrorism in Gaza and elsewhere, Iran can be expected to accelerate advances in its nuclear weapons program. Reciprocally, Israel will have to hasten its ongoing assessments of national survival options, both immediate and longer-term. These existential options include an eleventh-hour preemption against pertinent Iranian hard targets and more conspicuous plans for protracted nuclear deterrence. Regarding preemption, where this option is judged promising in operational terms, it could also represent "anticipatory self-defense" under international law. Regarding more conspicuous plans for nuclear deterrence, Israel will need (1) to shift from “deliberate nuclear ambiguity” to “selective nuclear disclosure;” and (2) to refine and make less opaque its generally presumed “Samson Option.”


Now that Prime Minister Benjamin Netanyahu has revealed plans for a longer war against Hamas, Israel will need to think more explicitly about the terrorist group’s patron: Iran. More specifically, these thoughts should center upon expected prospects for Iranian nuclearization. Even a pre-nuclear Iran could precipitate a “limited” nuclear war with Israel by using radiation dispersal weapons against Israeli civilians or by firing non-nuclear rockets at Israel’s Dimona nuclear reactor. In such realistic scenarios, Israel could feel compelled to use “proportionate” nuclear weapons against Iran to gain “escalation dominance.” Any such gain could allow Israel to maintain an upper hand in competitive risk-taking with Iran.

There is another scenario that is widely ignored publicly but warrants growing concern among military strategists in Israel. Because pre-nuclear Iran has very close and ongoing relations with an already-nuclear North Korea, that Islamic state could sometime threaten Israel with indirect nuclear retaliation from Pyongyang. In this ironic but not unimaginable narrative, a more powerful North Korea would become the proxy or surrogate of a less-powerful (not-yet-nuclear) Iran.

What would happen next? This raises a vital question for Israel to tackle immediately. It is a question that should be approached dialectically, sequentially, in continuously disciplined patterns of asking and answering and then asking some more.

Though an Israeli act of anticipatory self-defense could be permissible under international law, Jerusalem would not want to involve itself in such a controversial military operation at such a difficult time. It follows, inter alia, that if Israel chooses to decline the preemption option, a number of significant nuclear deterrence enhancements would be needed. These enhancements would concern improved ballistic missile defenses and an incremental discontinuance of deliberate nuclear ambiguity. More commonly, such ambiguity-related deterrence issues are referred to as Israel’s “bomb in the basement.”

There are assorted details. It will be necessary for Israel to communicate unambiguously to Iran that Israel’s nuclear forces are sufficiently secure from Iranian first-strikes and sufficiently capable of penetrating Iran’s active defenses. It will also become necessary to convince Iran that Israel’s nuclear weapons are operationally “usable,” that is, not of such injuriously high yield as to be implausible or irrational in real-world settings. In another strategic irony, the deterrent efficacy of Israel’s nuclear forces could vary inversely with its perceived destructiveness. Here, seemingly low-yield nuclear forces could sometimes offer more credible threats of “unacceptable damage” than would presumptively high-yield nuclear forces.

There is more. Among other things, Israel should be attentive to transformations of nuclear strategy underway in Islamic Pakistan. Observable in its own adversarial and already nuclear dyad with India, Islamabad has tilted openly toward smaller or "tactical" nuclear weapons. Since Pakistan first announced a test of its 60-kilometer Nasr ballistic missile back in 2011, the country’s well-disclosed emphasis on tactical or theater nuclear weapons (TNW) appears designed to more effectively deter a conventional war with India. By threatening to use relatively low-yield or “battlefield” nuclear weapons for retaliations, Pakistan hopes to appear less provocative to Delhi. More specifically, with such an unhidden stance, Islamabad is calculating that Pakistan is less likely to elicit nuclear reprisals from India during any mutual search for escalation dominance.

Conceptually, Israel vs. Iran is not analogous to India vs. Pakistan. For Israel, any nuclear retaliatory threats, whether still ambiguous or newly disclosed, would need to deter Iranian nuclear attack. Still, just as Pakistan has assuredly calculated the risks and benefits of theatre nuclear deterrence to curb unprecedented escalations from conventional to nuclear conflict, so too might Israel reason as follows: Because theatre nuclear weapons threats could better prevent the onset or acceleration of a conventional war than would high-yield strategic weapons, it could also better prevent the onset of an escalation-driven nuclear war with Iran.

In reaching complex strategic conclusions, correct meanings can be counter-intuitive. To wit, in certain more-or-less predictable circumstances, the credibility of Israeli nuclear deterrent threats could be undermined by perceptions of a too-destructive nuclear force. A compelling reason for Jerusalem to move away from deliberate nuclear ambiguity would therefore be to communicate to Iran that Israel’s nuclear retaliatory weapons were not too large for actual operational use.

In matters of nuclear deterrence, size could matter, but not necessarily as a direct variance. Accordingly, Iran’s calculating decision-makers could at some point conclude that Israel’s nuclear deterrence credibility varied inversely with the destructiveness of its nuclear forces. In such circumstances, prima facie, Israel would be better served by its presumed theatre nuclear weapons.

Concerning Israel’s nuclear forces and doctrine, Israel’s decision-makers will need to proceed more explicitly with another basic choice. This decision would concern the core distinction between "mutual assured destruction” and "nuclear war fighting.” In relevant military parlance, mutual assured destruction strategies are also called "counter-value" strategies (MAD). A common synonym for nuclear war fighting strategies is “counter-force.”

These strategies are typically presented as alternate forms of nuclear deterrence, forms in which an adversarial state targets its strategic weapons on a designated enemy state’s civilian populations and/or its supporting civilian infrastructures. Though seemingly in violation of humanitarian international law (the law of armed conflict) because it would appear to disregard the obligation to protect noncombatants whenever possible, it remains reasonable to argue that selected targeting doctrines could either reduce or enlarge the probability of a nuclear war. For Israel, there are serious survival implications for choosing one core strategy or the other. It is also reasonable to assume that Israel has opted for some sort of "mixed" (counter-value/counterforce) nuclear targeting doctrine.

There is more. By favoring counter-value targeting in a selected “mix,” Israel would be accepting an enlarged risk of "losing" any nuclear war that might still arise. By definition, counter-value-targeted nuclear weapons would not destroy military targets. If, on the other hand, Israel were to opt for nuclear deterrence based primarily on counter-force targeting, its Iranian enemy could feel especially threatened, an unstable condition that would then likely heighten the prospect of an actual nuclear exchange.

Going forward, Israel's decision on how best to configure counter-value and counter-force doctrines should be based, in part, on prior investigations of:

(1) Iran’s inclinations to strike first; and

(2) Iran’s inclinations to strike all-at-once or in stages.

If Israeli strategic planners should assume that a nuclear Iran is apt to strike first and to strike in unlimited fashion, Israeli counter-force-targeted warheads, used in retaliation, would probably hit only empty launchers. In such circumstances, Israel's only rational application of counter-force doctrine could be to strike first itself. If, for whatever reason, Israel were to reject all still-available preemption options, there would be no cause for Jerusalem to opt for a counter-force strategy. From the standpoint of persuasive intra-war deterrence, a counter-value strategy would then prove more appropriate.

If Israeli planners were to assume that a nuclear Iran is apt to strike first and in a limited fashion, holding some significant measure of nuclear firepower in reserve for follow-on strikes, Israeli counter-force-targeted warheads could still have meaningful damage-limiting benefits. Here, counterforce operations could serve both an Israeli preemption, or (should Israel decide not to preempt) an Israeli retaliatory strike. If an Israeli first-strike were intentionally limited, perhaps because it would have been coupled with credible assurances of no further destruction in exchange for a more rapid end to hostilities, these operations could serve the interests of an Israeli counter-retaliatory strike. Conceivably, of course, Israel's attempt at intra-war deterrence could sometime fail altogether, occasioning the need for follow-on strikes to produce desperately needed damage-limitation.

Israeli preparations for nuclear war-fighting should not be understood as a distinct alternative to preparations for nuclear deterrence. Instead, such preparations should be seen as essential and integral components of Israeli nuclear deterrence. A vital connection could then emerge between likely prowess or success in war, and the persuasiveness of pre-war nuclear deterrence.

In his 1982 book, The Bar Kokhba Syndrome, Yehoshafat Harkabi, a former Chief of Military Intelligence in Israel, examined a calamitous Jewish-historical event in the second century (132-135 AD/C.E.). Harkabi was trying to understand how an ill-fated ancient uprising could have pushed the Jewish People to the outer margins of history, and, more importantly, what specific strategic lessons could be learned from “Bar Kokhba.” He concluded that (1) “In policy-making, to take a risk and to make sacrifices occasionally is necessary, but there is a limit to the dangers worthy of risk, for national existence is never to be jeopardized;” and (2) “…in (specifically) nuclear circumstances, refrain from a provocation for which the adversary may have only one response, nuclear war.”

-Understood in terms of Israel’s most pressing security concerns, Harkabi would have correctly favored any reasonable measures to prevent Iran from becoming fully nuclear.

-Failing a viable preemption option, he would have likely settled for stable nuclear deterrence between these two enemy states.

Though preferred with reluctance, this logic-based acceptance could still have convinced Tehran that any use of its nuclear weapons would be irrational.[1] At the same time, it is always possible that a particular Iranian leadership would in fact be irrational. If such a worst-case enemy complication were anytime foreseeable in Jerusalem, Israel’s only rational response option could lie in preemption.

René Beres was educated at Princeton (Ph.D., 1971) and is the author of many books and articles dealing with Israeli nuclear strategy. His articles have been published in the Harvard National Security Journal (Harvard Law School); The International Journal of Intelligence and Counterintelligence; Parameters: Journal of the US Army War College;International Security (Harvard); Yale Global; Modern War Institute (West Point); The War Room (Pentagon); Air-Space Operations Review (USAF); Israel Journal of Foreign Affairs; Herzliya Conference Working Papers (Israel); The Jerusalem Post; US News & World Report; and The Atlantic. Emeritus Professor of International Law at Purdue, Dr. Beres' twelfth book Surviving amid Chaos: Israel’s Nuclear Strategy, was published by Rowman and Littlefield in 2016; 2nd ed., 2018.

[1] Crucial to Israel’s success with stable nuclear deterrence would be continuously conspicuous progress in submarine-basing. See by this author and a former NATO Supreme Allied Commander, Atlantic: Louis René Beres and (Admiral/USN/ret.) Leon "Bud" Edney, "Israel's Nuclear Strategy: A Larger Role for Submarine Basing," The Jerusalem Post, August 17, 2014; and Professor Beres and Admiral Edney, "A Sea-Based Nuclear Deterrent for Israel," Washington Times, September 5, 2014.