In 1996, I asked one of Israel's top security officials, “Are you opposed to Iran having nukes or are you opposed to the ayatollahs having nukes.” Without hesitation he answered, “The latter.”

This revealing comment offers an important insight into the source of Israel's current anxiety about the budding US-Iranian rapprochement. There are two dimensions to this concern. The first, and less important, is the bomb itself as a practical instrument of war. The second, and more significant, factor is Iran's ability to reduce Israel's strategic hegemony over a region spanning — as former Prime Minister Ariel Sharon once declared — from Morocco to Pakistan.

For two decades, Israel has been the engine behind the international effort to sanction Iran for its nuclear policies. This campaign offers a telling indication of Israel's power to shape the international agenda — the kind of power that it may now be losing. The very fact that Israel's militant rejectionist agenda toward Iran is now being challenged — by Western powers led by the United States no less — is at once evidence of Israel's reduced, if still substantial influence, and to Israeli policymakers worrisome proof that a zero-sum mentality that governs Israel's view and much of the Western view of Iran is now under critical review.

Yet even today, Israel’s concerns are more nuanced than its bombastic and, at times, hysterical campaign against Iran would suggest. Israel remains less concerned about Iran’s nuclear capabilities than about the character of the regime ― that is, who will have a finger on the button. And a parade of security professionals — some of them politicians such as Ehud Barak and others such as Mossad's chief Tamir Pardo — do not see a nuclear-armed Iran as an “existential threat.”