If not, and no diplomatic fix to the nuclear issue is possible, American-Israeli understandings will be required on a military option. Either way, neither the United States nor Israel can avoid a public falling out over Iran or a major split over how to manage the problem.

Simply put, the U.S.-Israeli relationship is too big to fail. That doesn't mean there won't be real differences over settlements, for example, that won't cause friction.

But on the two biggest issues of the day, how to manage Iran and the Palestinians, there can't be solutions without close Israeli-American cooperation.

It's legacy time. This is Obama's last term as president and perhaps Netanyahu's last term as prime minister. Obama doesn't want to be the U.S. president on whose watch Iran crossed the nuclear weapons threshold and certainly neither does Bibi want to be the Israeli prime minister held responsible.

It would be nice to imagine that the two can sit down and reach a broad strategic understanding -- first we deal with Iran, and if we succeed through diplomacy or even war, then let's find a way to preserve the two-state option for Israel and the Palestinians.

But even if this doesn't happen, these two leaders are inexorably bound together. They're never going to love each other. But I'm betting they'll find a way to get by without a major fight neither wants. The fact is the protection of Israeli and American interests and regional stability in a volatile, turbulent Middle East depends on it.

Follow @CNNOpinion on Twitter

Join us at Facebook/CNNOpinion