“Never again!”

Jews around the world, and well-meaning people of all faiths, took this solemn oath following the Holocaust. Israel was established to be the nation-state of the Jewish people, in which their unique contribution to world culture would flourish even more. It was also designed to ensure that the darkest hours of the past could never recur.

There is a deep debate within Israel itself about the Iranian nuclear program. Many believe that a nuclear Iran would pose an existential threat in the truest sense of the word and thus that Israel must do everything in its power to prevent this from happening.

Others believe that Israel could, in extremis, live with a nuclear Iran, and while it should do what it can within reason to prevent this, it need not do everything that it possibly can. No one in Israel doubts that the threat is dire, and even those who have criticized the premier and defense minister most stridently in recent months – including former heads of the Israeli defense establishment – recognize that military action may ultimately prove necessary.

Prime Minister Binyamin Netanyahu is clearly in the existentialist camp and is determined to prevent Iran from going nuclear. If one can be critical of some of his policies in other areas, he deserves great credit for having forced the international community to finally get serious about Iran.

Cynical and unfortunate though this may be, the unprecedented international sanctions now in place – likely to soon be further strengthened – are a function of (vastly overstated) Western concerns over the ramifications of an Israeli strike, at least as much as their fear of a nuclear Iran.

ADMITTEDLY, NETANYAHU overreached, trying to push US President Barack Obama too hard to make the kind of public commitments that Israel would like to see on Iran, and thereby exposing fissures in the US-Israeli relationship, a worrisome outcome which must be rectified. Like many Israelis, I also have misgivings regarding his repeated allusions to 1938 and the eve of the Holocaust.

Then, as now, fanatical leaders called for Jewish extermination, while an irresolute, self-preoccupied West, failed to take effective action. The USA, however, is a very different country from what it was in 1938, and while one can legitimately believe that Obama should take even firmer action, he has done more than any other Western leader.

Moreover, today’s IDF makes any comparison to 1938 moot.

Israel cannot be destroyed today.

Indeed, the real danger is probably not that Iran would ever use nukes, though this can never be discounted entirely and the margin of error is entirely unacceptable, but the extraordinarily dangerous influence a nuclear capability would provide it.

Israel may, or may not, ultimately be forced to take military action. One thing should be clear to all: no one in Israel takes this eventuality lightly, is triggerhappy, or will act before what they believe to be the last minute possible. No one wants to see the sanctions succeed and a diplomatic resolution more than Israel.

Only Israel, however, bears responsibility for its security. The pros and cons of a military strike can be legitimately argued and there is no single right answer.

Those who have an unwavering view in either direction are, I believe, simplistic and unrealistic.

OPPONENTS WILL correctly note what may be a severe Iranian response against Israel (primarily through Hezbollah), the possibility of some response against Saudi or other regional targets and against American and Western interests, as well as a spike in oil prices.

Most importantly, they will stress that the Iranian program can no longer be destroyed completely, since they already have the technology, and thus that even a successful attack will only achieve a few years delay. Proponents will argue that the Iranian response against Israel is likely to be far more limited than many fear, the response against Arab and American interests minimal, if not almost nonexistent, and most importantly, that a few year gain may prove to be vital.

This period would be used to further increase international pressure on Iran and to continue subversion and other preventative measures, and sooner or later the Iranian regime will fall. Remember, it was the mass demonstrations in Iran of June 2009 that was a harbinger of the Arab Spring.

We all wish to see a diplomatic resolution, and all indications are that Israel still believes that it has some, though not much, time.

Following Yom Kippur, it behooves us all – Jews and non- Jews – to reflect on the enormity of the stakes and what the oath of “never again” means in practical policy terms.

The writer, a senior fellow at Harvard’s Kennedy School of Government, was a deputy national security adviser in Israel during Labor and Likud governments. He is the author of Zion’s Dilemmas: How Israel Makes National Security Policy.