It has now been almost five years since the Project Daniel group advised former prime minister Ariel Sharon on how to deal with Iranian nuclear weapons. Our report, Israel's Strategic Future, urged the prime minister to enhance Israel's deterrence and defense postures, to consider an end to deliberate nuclear ambiguity in certain situations, and to refine pertinent preemption options.
Under no circumstances, we concluded, should Israel entertain any hope of coexisting long-term with a nuclear Iran.
Today, Israel's core plan for active defense against future Iranian nuclear missiles remains the Arrow anti-ballistic missile program. Although this plan is sound as part of a much broader security strategy, it wouldn't suffice in the case of a nuclear Iran. This plan must be augmented by improved Israeli deterrence and by corollary preparations for defensive first strikes against relevant Iranian hard targets.
A possible Israeli-Iranian "balance of terror" should not be compared to US-Soviet deterrence during the Cold War. A presumed balance with Iran could never assure the required rationality of decision-makers in Teheran. Moreover, terrorist proxies instead of missiles could deliver Iranian nuclear weapons and materials. This fact underscores Jerusalem's critical need to maintain and codify appropriate preemption options.
All deterrence logic rests on the key assumption of rationality. An Iran that might value certain religious expectations more highly than its own national survival could well be immune to threats of nuclear retaliation. Even assuming foreign sources are right about Israeli capabilities, faced with this improbable, but entirely conceivable prospect, Israel cannot depend upon even a "perfect" combination of nuclear deterrence and ballistic missile defense.
IF THE Arrow Missile Defense System were 100% efficient in its expected reliability of interception, even an irrational Iranian adversary armed with nuclear and/or biological weapons could be kept at bay without defensive first strikes or threats of massive retaliation. After all, were Israel's reported nuclear deterrent neutralized by a fanatical Iranian enemy willing to risk a massive counter-city Israeli reprisal (a suicide-bomber writ large), any first-strike by Teheran could still be blocked by the Arrow.
This sounds better in theory than in practice. In the real world of international conflict, ballistic missile defense (BMD) could not attain such needed levels of reliability. No BMD system, even the successfully tested Arrow, can be leakproof. Yet, where the warheads upon an enemy's missiles would be nuclear, no level of leakage could be tolerable.
Israel cannot fully depend upon its anti-ballistic missiles to defend against any future WMD attack from Iran any more than it can rely only on its presumed nuclear deterrence. This means that even the best possible Arrow system, complemented by credible and capable nuclear threats, would not obviate Israel's preemption option.
NONE OF this is to suggest that Arrow fails to play an important role in protecting Israel. To be deterred, a rational Iranian adversary would always need to calculate that Israel's reported second-strike forces are substantially invulnerable to any first-strike aggressions. With the Arrow in place, Iran would require, among other things, many more missiles to achieve an assuredly destructive first-strike against Israel. Israel's BMD system will at least compel a rational enemy in Teheran to delay any intended first-strike attack, allowing Israel to buy time until Iran could deploy a more fully capable nuclear and/or biological offensive missile force.
Up front, this is good news for the Jewish state. But Israel still faces an Iran whose undisguised preparations for Israel are authentically genocidal, and whose leaders may not always be rational. Awaiting the Shi'ite apocalypse, President Mahmoud Ahmadinejad may seek to convince other Iranian leaders that war with Israel is necessary for "redemption."
NOWHERE IS it written that Israel must sit back passively and respond only after a nuclear and/or biological attack has been absorbed. Israel has the same right given to all states to act preemptively when facing an annihilatory assault. Known formally as "anticipatory self-defense," this right is affirmed in international law. The 1996 Advisory Opinion of the International Court of Justice on the legality of the threat or use of nuclear weapons even extends such authority to the preemptive use of nuclear weapons in certain existential circumstances.
Israel must continue to develop, test and implement an interception capability to match the growing nuclear missile threat from Iran. It must also continue to prepare for critical preemptions. If Iran should be allowed to become nuclear, Israel would have to fully enhance the credibility of its presumed nuclear deterrent and deploy a recognizable second-strike force, adequately hardened, multiplied and dispersed. This strategic force would be fashioned to inflict a decisive retaliatory blow against selected enemy cities.
Every state has the inherent right under international law to ensure its own survival. Israel is no exception.
Beres is professor of international law at Purdue University. He was chair of Project Daniel and is the author of many major books, articles and monographs on nuclear strategy and nuclear war. MK Ben-Israel (Kadima) is a retired IDF major-general, former chair of the Israeli Space Agency, a professor at Tel Aviv University, and a member of the Knesset Foreign Relations and Security Committee. He was a member of Project Daniel.