Following President Obama´s strong renunciation of "containment" and his expression of willingness to use military force as a last resort to prevent Iran from developing nuclear weapons, some on the left continue to oppose any threat to use the military option. Leading this approach is Fareed Zakaria, who recently on his CNN program, characterized the Obama policy as "a serious error," and called instead for a "robust policy of containment and deterrence."

But the policy that Zakaria is proposing is anything but robust. To the contrary, it is a call for inaction. It presumed that Iran will be allowed to develop nuclear weapons, but that they will be deterred from actually using them by the threat of nuclear retaliation. Zakaria points to the fact that deterrence succeeded in preventing war between the United States and the Soviet Union, as well as between India and Pakistan. He claims that each side was effectively deterred by the threat of mutually assured destruction. He says it will work equally well with Iran.

Let us pause for a moment to understand precisely what a policy of deterrence entails. Any such policy is based on the promise that if one side launches a nuclear attack, the other side will retaliate with an equally devastating nuclear attack, thus assuring the destruction of both societies and the deaths of millions of innocent civilians. The first question therefore is whether the United States would actually be willing to retaliate against a nuclear attack on Israel by dropping nuclear bombs on Tehran, killing millions of its civilian inhabitants. The second question is whether any civilized country—the United States or Israel—should be willing to kill millions of Iranian civilians because their leaders made a decision to use nuclear weapons against Israel or the United States. The third question—and the one never asked by advocates of deterrence—is whether it would be legal, under the laws of war, to target millions of civilians in a retaliatory nuclear attack.

These are the kinds of questions that Fareed Zakaria and his dovish colleagues refuse to ask. And the reason they refuse to ask these hard questions is precisely because we know the answers they would give: They would be categorically opposed to any retaliatory attack that targeted civilians in a tit-for-tat implementation of a mutually assured destruction policy of deterrence. If you don´t believe me, ask him!

As to the legality of nuclear deterrence, the International Court of Justice issued a decision in 1996, in a case challenging the lawfulness of using, or threatening to use, nuclear weapons. The majority decision declined "to pronounce…on the practice known as ´the policy of deterrence´." It did rule unanimously, however, that any "threat or use of nuclear weapons" must "be compatible with the requirements of the international law applicable in armed conflict, particularly those of the principles and rules of international humanitarian law…" These rules, of course, generally forbid the targeting of civilian population centers and require proportionality even in the bombing of military targets. Since nuclear weapons are, by their nature, virtually incapable of destroying military targets without also inflicting countless civilian casualties, it would seem to follow that they could not be used except against remote military targets, such as ships and submarines on the high seas, or armies in isolated deserts or mountains. In a divided vote, the court ruled that:

"the threat or use of nuclear weapons would generally be contrary to the rules of international law applicable in armed conflict…"

"However, in view of the current state of international law, and of the elements of fact at its disposal, the Court cannot conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defence in which the very survival of a State would be at stake."

In other words, it would be unlawful for the United States to threaten or use nuclear weapons as a deterrent, since its "very survival" would not be at stake, but it might be lawful for Israel to do so because it is a small state whose very survival would, in fact, be at stake were it to be attacked by nuclear weapons.

Menachem Begin, the Israeli Prime Minister who ordered the preventive attack on Iraq´s nuclear reactor in 1981, expressly renounced mutually assured destruction as a policy. He said that Israeli "morality" would never permit a retaliatory attack against an Iraqi city: "The children of Baghdad are not our enemy."

A preventive attack, on the other hand, is always directed against a military target. Only one person—a nuclear technician—was killed in the attack Begin authorized.

It would appear to be ironic that Zakaria, and others who purport to be "doves", would favor a mutually assured destruction policy that threatens the deaths of millions, over a preventive policy that targets military nuclear facilities. But it is not at all ironic, since such doves would be against actually carrying out the threat that is central to any credible policy of deterrence. For them, deterrence is a bluff—a hollow threat and the Iranians would see right through it.

That´s why President Obama is correct in renouncing containment and insisting that he isn´t bluffing when he says Iran will not be allowed to develop nuclear weapons, even if it takes a surgical military strike to stop them.

I am not here arguing in favor of a preventive attack on Iran at this time. I am arguing against reliance on a policy of deterrence and containment, because I don´t believe it will work in relation to Iran, Israel and the United States.

What if deterrence and containment didn´t work, and Iran were to fire nuclear rockets at Israeli cities? Those who now advocate robust deterrence—instead of surgical prevention—would simply say to the remaining Israelis: "Woops. We were wrong. Sorry. We´ll build you a new Holocaust Museum."