"Do you know what it means to find yourselves face to face with a madman?" inquires Luigi Pirandello's, Henry IV. "Madmen, lucky folk, construct without logic, or rather with a logic that flies like a feather."
In the absurd theatre of modern world politics, decisions based on logic can quickly crumble before madness. Looking ahead, especially if madness and nuclear weapons capacity should sometime happen to coincide, a targeted country's vulnerabilities could become intolerable. For Israel, a nation-state smaller than America's Lake Michigan, any such combined enemy development must always be prevented.
For Israel, however, not all possible forms of enemy abnormality would necessarily exhibit madness. There could also emerge one or several adversaries, both state and sub-state, who are not genuinely mad, but are nonetheless irrational. Significantly, irrationality, at least in world politics, is not the same as madness, and must therefore be treated differently.
Whereas mad enemies would be unpredictable, and not subject to any calculable forms of deterrence, a "merely" irrational state enemy could still maintain a consistent and transitive hierarchy of preferences. This means that although a presumptively irrational enemy might not value its national survival most highly - indeed, this is the standard definition of irrationality in world politics - it could still be deterred by credible Israeli threats to harm whatever is valued above all. In the Islamic Middle East, for example, this apparent object of greatest value is apt to concern certain palpable feelings of religious obligation.
Also worth noting is that a fully genocidal state enemy of Israel could be rational, irrational, or mad, and should be dealt with in Jerusalem on the basis of its particular decision-making classification.
For Israel's strategic planners, all of this implies, among other things, a basic obligation to (1) categorize the beleaguered country's principal enemies, both state and sub-state, according to optimally explicit criteria of madness versus irrationality; (2) comprehensively identify all composite enemy threats, whether conspicuous or inconspicuous; and (3) skillfully fashion this resultant calculus of anticipated threats into a purposeful and thoroughly coherent deterrence policy.
Israel must continue to strengthen its historically "ambiguous" nuclear deterrent, and prepare, in short order, to take its bomb "out of the basement."
In undertaking such a determinedly analytic effort, Israeli military planners will first need to consider very complicated interactions or "synergies" between the composite threats, and between these particular synergies with Israel's available policy options. This second set of decisional considerations calls for a corollary focus on all possible "synergies of synergies," an intellectually challenging focus that will insistently demand a parallel understanding of chaos in regional and world politics.
Oddly, regional or global chaos, which is always much more far-reaching than simple anarchy - that is, than the structurally-created condition of decentralized authority that has been with us since the Peace of Westphalia (1648) - may still reveal discernible shape and form. How, precisely, should this usually dense or opaque "geometry" of chaos best be deciphered by Israel? Going forward, this is a question of understanding that Israeli planners can choose to ignore only at their country's existential peril.
To best augment Israel's still-developing strategy of deterrence, including nuclear deterrence, Jerusalem must further accelerate its already-ambitious plan for suitable active defenses. At the same time, no matter how promising the interpenetrating Israeli protection systems and their components happen to be, there exist urgent reasons for MOD/IDF never to become too dependent upon active defenses. This is because no system of ballistic missile defense (BMD) can ever be dependable enough to preclude or minimize a core strategy of deterrence.
Even with the very best integrative, multi-layer systems that presently include Arrow, Iron Dome, and David's Sling, there may still be a too-high level of "leakage." This risk becomes especially obvious in those increasingly plausible cases where the incoming warheads could be biological and/or nuclear.
Israel must continue to strengthen its historically "ambiguous" nuclear deterrent, and prepare, in short order, to take its bomb "out of the basement." The point here would not be to clarify the already obvious, but instead, to signal all prospective aggressors that Israel deploys both usable and sufficiently invulnerable retaliatory forces to reliably penetrate any determined aggressor's active defenses. Of course, this point can prudently apply only to rational state enemies.
With regard to mad or irrational enemy states, and to all sub-state or terrorist-group enemies - rational, irrational, or mad - any threats of nuclear retaliation would likely be irrelevant, and hence unpersuasive. Here, apart from already-mentioned active defenses, Israel might also need to rely upon certain apt forms of defensive first-strikes. Under relevant international law, any such life-saving resorts to "preemption" could more-or-less correctly be described as "anticipatory self-defense."
We may readily presume that Israel already maintains a secure and penetration-capable nuclear retaliatory force. This second-strike capacity, hardened and dispersed, should now be made more recognizably ready to inflict unacceptably damaging reprisals. In this connection, as an exclusively "counterforce" targeting posture could create major deterrence liabilities for Israel, the Jewish State's primary nuclear targets should be identifiable enemy cities. From the vital standpoint of enhancing such alternative or "counter value" forms of nuclear deterrence, it may also soon become time for Israel to release bits of carefully selected information concerning its sea-based (submarines) retaliatory forces.
There are further meaningful nuances. Israel must clarify that Arrow and its other active defenses would always operate together with Israeli nuclear retaliations. This point is central. Always, Israel's pertinent state adversaries must be made to understand that, wherever appropriate, Israel’s defensive deployments would never supplant or even render less probable an unacceptable Israeli nuclear reprisal.
On expected Israeli preparations for nuclear war-fighting, these should never be interpreted as a distinct policy alternative to nuclear deterrence. On the contrary, such preparations should always be taken as essential and integral components of Israeli nuclear deterrence. At all times, the overriding purpose of Israel's nuclear forces, whether still ambiguous, or newly-disclosed, should remain deterrence, never actual military engagement. As was pointed out byProject Daniel back in 2004: "The primary point of Israel's nuclear forces must always be deterrence ex ante, not revenge ex post."
This sensible prescription echoed the much earlier and plainly pre-nuclear advice of Sun-Tzu's The Art of War. According to the ancient Chinese strategist: "Subjugating the enemy's army without fighting, is always the true pinnacle of excellence." Sun-Tzu, as usual, was right-on-the-mark.
There is more. In the future, certain enemy nuclear harms could be directed toward Israel, not only via direct missile strike, but also by terrorist-proxy platforms, or via rocket attacks on Israeli nuclear reactors. These platforms could include cars, trucks, and boats.
Should a newly-nuclear adversary of Israel ever decide to share certain weapons-usable materials and/or scientific personnel with terror-group surrogates, the Jewish State might then have to face a substantially heightened prospect of nuclear terrorism. Ultimately, at least in principle, the multiple perils posed in such conceivable scenarios could even impact American cities.
The latent "good news" in all of this speculation is that deterrence of an enemy state that might not value its own physical survival above all else could still work. For Israel, successfully deterring a potentially irrational nuclear adversary need not be judged out of the question. Irrationality, we should recall, is not the same as madness, and is still compatible with a fully determinable order of national values or preferences.
It is possible, and perhaps even probable, that, for the foreseeable future, authoritative enemy leadership elites will remain entirely rational, and thus continue to value their respective countries' physical survival more highly than any other preference, or combination of preferences. These elites would stay subject to the very same "normal" threats of retaliatory destruction that would affect other rational states in world politics. While there can never be any absolute guarantees of witnessing such a distinctly preferred scenario, it is also premature to conclude that a newly-nuclear foe, whether rational or irrational, would lash out viscerally at Israel, with no evident regard for consequences.
In any event, as it will not be up to Israel to chose whether its most fearsome adversaries are mad, irrational, or rational, Jerusalem will need to prepare systematically to meet all three categories of foe. To begin, this will mean the prompt construction of a usable matrix of options, one that suitably correlates various damage-limiting remedies with specific threat orientations.
Those who are mad, we learned from playwright Luigi Pirandello, construct "without logic," but those who are merely irrational may still reveal a decipherable and useful logic.
For Israel's strategic planners, this utterly core distinction is well worth bearing in mind.
 For several years, at least, Iran has made expressly genocidal threats against Israel, threats in explicit violation of the 1948 Convention on the Prevention and Punishment of the Crime of Genocide. Additionally, on March 9, 2016, Iran test-fired two ballistic missiles, with the phrase "Israel should be wiped off the Earth" written in Hebrew.
 See the author's just-published book, Surviving Amid Chaos: Israel's Nuclear Strategy (Rowman & Littlefield, 2016).
 On these issues, see Louis René Beres and Major-General (IDF/res.) Isaac Ben-Israel, "Think Anticipatory Self-Defense," The Jerusalem Post, October 22, 2007; Professor Beres and MG Ben-Israel, "The Limits of Deterrence," Washington Times, November 21, 2007; Professor Beres and MG Ben-Israel, "Deterring Iran," Washington Times, June 10,2007; Professor Beres and MG Ben-Israel, "Deterring Iranian Nuclear Attack," Washington Times, January 27, 2009; and Professor Beres and MG Ben-Israel, "Defending Israel from Iranian Nuclear Attack," The Jewish Press, March 13, 2013.
 On Israeli submarine-basing options, see: 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. Admiral Edney was NATO Supreme Allied Commander, Atlantic.
 See Bennett Ramberg, "The Next Chernobyl May Be Intentional," Reuters, Edition: U.S., April 26, 2016.
 See, earlier, Louis René Beres and (General/USAF/ret.) John T. Chain, "Could Israel Safely Deter a Nuclear Iran?" The Atlantic, August 9, 2012; and Professor Beres and General Chain, "Living With Iran," BESA Center for Strategic Studies, Israel, May 2014. General Chain was Commander-in-Chief, U.S. Strategic Air Command (CINCSAC).
Louis René Beres (Ph.D., Princeton, 1971), is Emeritus Professor of International Law at Purdue. The author of many major books and articles in the field, including some of the very earliest publications on Israeli nuclear strategy, he was Chair of Project Daniel (Israel, 2003). Professor Beres' just-published book is titled Surviving Amid Chaos: Israel's Nuclear Strategy (Rowman & Littlefield, 2016).