The different reactions in Washington and Jerusalem to the Iranian elections are, first and foremost, a matter of history and personality. Americans are historically optimistic by nature and tend to “see the opportunity in every difficulty,” as Winston Churchill once said. Israelis, in particular, and Jews, in general, are genetically and justifiably pessimistic, and usually “see the difficulty in every opportunity.”

This gap is compounded by the divergent ideologies of the two main protagonists: When Prime Minister Benjamin Netanyahu insists on being the world’s party-pooper by warning against “wishful thinking” about Iran’s newly elected president, Hassan Rowhani, he is validating the fatalistic right-wing world view, shared by the hard American right, of an inherently hostile Muslim world.

When White House Chief of Staff Denis McDonough, on the other hand, speaks of the Iranian ballot as “a sign of potential hope," he is invoking the idealistic left-wing belief, shared by Presidents Barack Obama and Shimon Peres, in the possibility of transformative change by means of dialogue and diplomacy.

From that point of view, Rowhani’s surprise election takes the world back four years, to 2009, when Obama was bent on courting Spiritual Leader Ali Khamenei and pledged to engage Tehran with “courage, rectitude and resolve.” The president may have shed some of the “naivete” that Israelis ascribe to him and he may have instituted a harsh sanctions regime against Iran, but it is hard to see him refusing a chance to resuscitate the largely still born “New Beginning” that he promised in his famous Cairo speech.

At that time, Obama was interested in reaching understandings with Iran, inter alia, in order to facilitate the withdrawal from U.S. troops from Iraq. Now he may be seeking ways in which Tehran could help him avoid similar complications in Syria. It stands to reason, in fact, that Obama may have postponed his decision to send military aid to the Syrian rebels had anyone informed him of the “Iranian Spring” that was about to break out in Tehran.

Thus, whether by Machiavellian design or the dictates of an unforeseen reality, Khamenei’s decision to allow Rowhani’s election to stand has already yielded significant dividends for Tehran. It has gained the Iranians a reprieve, at least for the time being, from the inexorable slide to ever harsher sanctions and possible US military action. And it has deprived Israel and its supporters of their most potent weapon against Iran’s nuclear plans: Mahmoud Ahmadinejad.

The outgoing president’s incessant provocations against world leaders and his vile denial of the Holocaust angered world public opinion and inflamed American Jews, who viewed him as Adolf Hitler incarnate. The shadow of its perceived inaction during the Holocaust spurred the American Jewish establishment to wage an unrelenting battle against Iran’s nuclear industry, under the banner of “Never Again.”

Rowhani, who has had the adjective “moderate” affixed to his name since his election as if he owns it, is certainly not cast in the Ahmadinejad mold - but the celebration of an impending “dawn of a new day," as Ehud Barak once famously called it, may be premature.

In a 2004 speech, while serving as Iran’s chief nuclear negotiator, Rowhani explained his modus operandi in the talks the then conducted with the EU-3, comprised of Britain, France and Germany. Swearing allegiance to Iran’s ultimate nuclear goals, Rowhani boasted "While we were talking with the Europeans in Tehran, we were installing equipment in parts of the [nuclear conversion] facility in Isfahan. By creating a calm environment, we were able to complete the work there.”

The difference between the incoming and outgoing presidents - in those years at least – was more style than substance, more tactics than strategy: Rowhani believed in putting on a face of moderation on the way to the same nuclear goals. True, Israel’s sourpuss is unbecoming and, yes, Rowhani may have changed his ways, but there is something to be said for Jerusalem’s demand, especially from Obama, that the burden of proof be placed squarely on the new president’s shoulders.