Found through RaceForIran.com, this article in the Council on Foreign Relations' Foreign Affairs publication by Ariel Ilan Roth explains, with an admirable amount of detail, the actual threat an Iranian nuclear capability poses to Israel.
Most observers believe that Israel’s preoccupation with Iran’s nuclear program stems from the fear that Iran would either use a nuclear weapon against Israel or give the bomb to one of its direct proxies, most likely Hezbollah. Given Tehran’s open hostility toward Jerusalem, such foreboding makes sense. But such a scenario is highly improbable.I've never heard "strong today, gone tomorrow" expressed explicitly by any Arab or Muslim leader. I'm curious about if Sadat ever really said that. My explanation for Egyptian and Saudi behavior is that the US has captured a lot of leverage over their policies. It is possible to twist pro-US policies to seem as if somehow they have a native strategic basis, but I usually do not do that. Just simply calling them puppets has more explanatory power than trying to figure out a rationalization that would claim anti-Zionist objectives are best met by appearing to everyone, including Israel's leaders and strategists, to cooperate with Zionism.
Since it is doubtful that Iran will use nuclear weapons against Israel or surrender control of the ultimate weapon to Hezbollah -- a point made recently by retired General Shlomo Gazit in Ma’arachot, the quarterly journal published by the Israeli military -- one can safely assume that the root of Israel’s Iranian obsession lies elsewhere.
Israel fears that Iran’s nuclear ambitions could undermine its qualitative superiority of arms and its consistent ability to inflict disproportionate casualties on adversaries -- the cornerstones of Israel’s defense strategy. Although some idealists dream of reconciliation in the Middle East based on a genuine and mutual recognition of all parties’ legitimate rights, most Israelis believe the key to enduring peace in the Middle East is convincing Israel’s adversaries that ejecting Israel through force is an impossible task not worth pursuing.
The development of nuclear weapons by Egypt or Saudi Arabia would pose a grave danger to the Jewish state, despite the fact that Egypt has signed a peace treaty with Israel. This is because leaders who have reconciled themselves to Israel’s existence -- including those of Egypt, Jordan, and certain segments of the Palestinian national movement -- have done so because they believed Israel was strong but unlikely to endure in the long term. (Egyptian President Anwar Sadat, for example, justified his pursuit of a peace process with Israel by comparing the Israelis to crusaders: strong today, gone tomorrow.) More broadly, as the Palestinian-American political scientist Hilal Khashan’s work on Arab attitudes toward peace has shown, the willingness of Arabs to make peace with Israel is a direct function of their perception of Israel’s invincibility. Just as an Iranian nuclear capability would imply a nuclear guarantee for anti-Zionist proxies, an Egyptian or Saudi nuclear capability would reduce incentives for other Arab states to make peace with Israel because, shielded under an Arab nuclear umbrella, they would no longer fear catastrophic defeat or further loss of territory.
The possibility that Israel may no longer be capable of forcing peace upon those who deny its right to exist is beginning to dawn on many Israelis. Whether Israel attacks Iran’s nuclear infrastructure or not, the time has come for Israel’s defense community to develop a strategic doctrine for long-term coexistence that does not rely on a posture of invincibility. But, given that widespread Arab acceptance of Israel’s right to exist does not appear to be on the horizon, most Israelis, including the current prime minister, insist that Israel’s most urgent strategic objective is to stop Iran from developing a nuclear weapon. Doing so would temporarily remove the threat of a regional nuclear cascade and maintain Israel’s superiority of arms. More important, it would hold at bay the suspicion that Israel may never attain true peace. This increasingly widespread fear has a toxic effect on national morale, is an existential threat to the Jewish state, and lies at the root of Israel’s obsession with the Iranian bomb.
The main effect an Iranian nuclear capability will have on Egyptian and Saudi policy is that it will make it slightly more difficult for members of their leadership communities to look themselves, each other and outsiders in the eye given their acquiescence to the US demand that they refrain from developing a nuclear capability. Maybe the example of Iran's nuclear capability will shame them into acquiring the same, but strategically both Saudi Arabia and Egypt should have worked to achieve nuclear capability a long time ago. They did not because the US demanded that they not. Their submission to US demands is more likely to continue, at least short term, than to be changed shortly after it is accepted that Iran is nuclear capable.
Roth does a poor job differentiating between a nuclear weapon and a nuclear capability. This is a very important distinction because there is, while Iran remains in the NPT, a much stronger legal and moral basis to demand Iran refrain from building a weapon than there is to demand Iran refrain from developing a capability. Roth points out that capability, even without a weapon, has a negative impact on Israel's strategic situation. When Roth says Israel's most important strategic objective is to prevent Iran from getting a weapon, he means prevent Iran from getting the capability to build a weapon. It is misleading to just slide back and forth between the two different concepts, but we see that more often than not in discussions of the nuclear issue by people who are sympathetic to Israel maintaining a monopoly of nuclear capability.
Roth also uses language such as "legitimate rights" and "Israel's right to exist" which injects his particular view of the project of Zionism into the analysis. Afrikaaner or White South Africa did not have a right to exist and the state did not have legitimate rights. Jewish majority Israel has no more or fewer rights than Afrikaaner majority territories of Africa. Fortunately despite his views Roth overcomes the temptation to cast Iran's nuclear program in more emotionally provocative terms at the cost of being less accurate. Many of the distortions we see in Western discussions of Iran's nuclear program come from feelings on the part of Western analysts that misleading the audience in a way that leads readers to conclusions that would make the survival of Israel more secure, even if those conclusions are false, is if not laudable then at least acceptable.
But Roth's main point that Israel calculates that its future depends on it having an unanswerable deterrent, which is put into question by Iran demonstrating that it has the capability to answer Israel's threats to use nuclear weapons on its neighbors, is exactly correct. Israel's regional monopoly on nuclear capability is essentially gone already. It is fortunate, if it is true, that this realization is, as Roth says "beginning to dawn on many Israelis"