As I discussed in part one of this post, the discussion of the impact of the U.S. presidential election on Israel tends to be exaggerated. Just as it is absurd to speak of a man who clearly has little genuine sympathy for the Jewish state as its best friend ever to sit in the White House (as Democrats falsely assert), it is equally foolish to claim that Israel’s survival hangs on the outcome, since the alliance between the two countries is so entrenched in our political culture that severing it is probably beyond the capacity of even a re-elected president. However, it is impossible to avoid the conclusion that four more years of Barack Obama will mean more tension between the U.S. and Israel that will undermine the relationship and encourage the Jewish state’s foes, to no purpose. Yet the inevitable spats over the peace process with the Palestinians pale in significance when compared to what may be Israel’s greatest current security challenge: a nuclear Iran.

Any account of the last four years of U.S. policy toward Iran must begin with the fact that President Obama has left himself very little room to maneuver out of a commitment to stop Tehran from acquiring a nuclear weapon. The president has been consistent in stating that he will not allow this to happen on his watch since he was first running for president in 2008. Since then, he has repeated this mantra and significantly elaborated on it while running for re-election. He has acknowledged that a nuclear Iran is a danger to U.S. security, rather than just an existential threat to Israel. This past March, the president specifically repudiated the possibility of “containing” a nuclear Iran but said that it must be stopped from attaining such a weapon. During the third presidential debate, he said the only deal he will accept with Iran is one that precludes their having a “nuclear program,” something that would preclude the sort of compromise favored by America’s European allies that would allow Tehran to keep its reactors and fuel–leaving open the possibility of a North Korea-style evasion of international diplomatic efforts.

Yet the question remains what will a re-elected President Obama do if the belated sanctions he imposed on Iran (and whose loose enforcement is itself an issue) do not convince them to give in to his demands? Will he keep the “window for diplomacy” open to allow the Iranians to go on delaying until they reach their nuclear goal? That’s something no one can know for sure, but which must haunt friends of Israel.

The worries about Obama and Iran center on doubts about whether he will keep his word about containment and no nukes for Iran. Given the president’s “hot mic” promise to Russia that he will be “more flexible” with the Putin regime if he is re-elected, it is reasonable to ask whether he will show just as much flexibility on this issue and either punt or craft some compromise that will leave the door open to a nuclear Iran some time in the future.

Obama’s defenders insist that he means what he says about stopping the Iranians. But critics ask why a president who has always shown a greater inclination to talk about the danger than to do anything about it would ever move on Iran. Obama’s instincts have always inclined him toward pursuing the sort of diplomatic activity that allows the Iranians to keep spinning their centrifuges. The president insists that he will not allow himself to be played for a fool by a series of talks whose only purpose is to let the Iranians run out the clock until their program becomes unstoppable. Yet he has specifically refused to agree to the sort of “red lines” that Iran would not be allowed to cross without risking U.S. action. The president’s palpable anger at Israeli Prime Minister Benjamin Netanyahu for making such a request reminded observers that throughout his presidency he has always seemed a lot more anxious about preventing the Jewish state from acting on its own against Iran than in stopping the ayatollahs.

Even if one takes Obama at his word on Iran in terms of his intentions, the idea that he has another year or two or three that he can use to wait out the ayatollahs while sanctions weaken them may be mistaken. The staying power of the Islamist regime should not be underestimated. Nor should we assume that there are years rather than months before the Iranian stockpile of enriched uranium safely stored in underground bunkers is so great that force will no longer be an option.

Lack of faith in Obama’s willingness to act on Iran is not just the product of the fact that he seems an unlikely candidate for launching a limited war on Iran over its nuclear program, though that is certainly true. The bigger problem is that the president is so in love with the United Nations and the idea of negotiations that it is hard to imagine that he will ever come to a moment where he will be willing to accept that diplomacy is no longer an option.

It is hardly an exaggeration to say that if Obama cannot be trusted to do the right thing on Iran — even if that means the use of force — that this will have a tremendous impact on Israel’s security as well as that of the United States. Should Israel ever conclude that Obama has no intention of doing more than talk about Iran it may decide to act on its own, a course that brings with it a host of military and diplomatic problems that are almost too great to contemplate.

While there is no way of knowing for sure what Obama will do, the reasonable doubts about him are part of the reason why the Iranians have been so confident about their ability to outwait the West.

In part three of this series of posts, I will discuss whether it is fair to assert that Mitt Romney will be different than Obama on Iran and other aspects of the U.S.-Israel alliance.