It has been six years since the special Project Daniel Group first advised on the unique threat of Iranian nuclear weapons in January 2003. Our detailed final report urged then-Prime Minister Ariel Sharon to enhance Israel's deterrence and defense postures, to consider an end to deliberate nuclear ambiguity if Iran should become nuclear and to suitably refine pertinent pre-emption options. It also concluded that Israel should not expect peaceful coexistence with a nuclear Iran, and that active national defenses should be strengthened.
Today, Israel's core plan for active defense remains the Arrow. To adequately protect against attack from Iran, however, this system of ballistic missile defense must be complemented by improved Israeli deterrence, and also by truly viable options for defensive first strikes against appropriate hard targets. Under no circumstances should it be assumed in Jerusalem and Tel Aviv that a stable "balance of terror" could be created with Tehran. The essential assumption of enemy rationality simply might not always be warranted. Any analogy between Iran and our own deterrence relationship with the former Soviet Union would be facile and out of place.
Of course, if the Arrow were entirely efficient, even an irrational Iranian adversary armed with nuclear and/or biological weapons could be kept at bay without defensive first strikes, and/or threats of retaliation. But no BMD system can ever be truly "leak-proof." Moreover, terrorist proxies in ships or trucks - not missiles - could deliver Iranian nuclear attacks upon Israel. In such low-tech but high-consequence assaults, there would be no benefit to any sort of anti-missile defenses.
Israel cannot depend upon its anti-ballistic missiles to fully defend against any future WMD attack from Iran any more than it can rely only on nuclear deterrence. This does not mean that the Arrow fails to play an important protective role as part of a larger security apparatus. It is a distinctly necessary part of Israel's security posture, but it is also not sufficient.
Every state has an indisputable right under international law to act pre-emptively when facing a potentially existential aggression. The 1996 advisory opinion of the International Court of Justice even extends such authority to the pre-emptive use of nuclear weapons in certain existential circumstances; but - at least for now - Israel could still undertake "anticipatory self-defense" without such weapons. It must be noted further that Russia has agreed to sell Iran its SA-20 strategic-range air defense system. Once deployed, this system would further complicate the success of any Israeli hard-target pre-emption.
If, for whatever reason, Iran should be permitted to proceed to become fully nuclear, Israel would - at a minimum - have to enhance the credibility of its presumed nuclear deterrent, and also to deploy a recognizable second-strike force. This optimally robust strategic force - hardened, multiplied and dispersed - would be fashioned to inflict a decisive retaliatory blow against selected enemy cities. Iran should understand, therefore, that the actual costs of any planned aggression against Israel would always exceed any conceivable gains.
The substantial dangers of a nuclear Iran would also impact the United States. While it could still be several years before any Iranian missiles could strike actual American territory, the United States could still be as vulnerable as Israel to nuclear-armed terrorist surrogates. In this connection, any American plan for a "rogue state" anti-ballistic missile shield would have the very same limitations as Israel's Arrow.
International law is not a suicide pact. When Iran still announces explicitly genocidal intentions while simultaneously and illegally developing nuclear weapons, Israel has absolutely no choice but to protect itself with the best means available. Hopefully, America's new president will promptly support this fundamental right of Israeli survival.
In the especially urgent matter of Iranian nuclearization, President Obama should also quickly acknowledge the overwhelming mutuality of strategic interest between Israel and the United States. Both countries are in the very same boat. A fully nuclear Iran would prove an intolerable hazard to New York, Washington and Los Angeles and to Haifa, Jerusalem and Tel Aviv.
Louis Rene Beres is professor of international law at Purdue University. He was chair of Project Daniel. Isaac Ben-Israel is a retired major general from the Israel Defense Force. He was chair of the Israel Space Agency and a member of Project Daniel.