To the extent that there are bitter divisions between the center and left of the Democratic Party on foreign policy issues, they have been forward-looking: Should the next Democratic president be a restorationist intent on reversing the Trump administration’s alliance-wrecking policies and reinstating America’s role as the lynchpin of a “liberal international order?” Or should that president rethink America’s role altogether, discarding the assumptions about the country’s capability and exceptionalism shared by administrations of both parties?

Not all the candidates for the 2020 Democratic nomination fit neatly into these descriptions, but nearly all of them lean noticeably in one direction or the other. This presumably has some implications for Israel: those closer to the traditional establishment view are seen as more likely to be pro-Israel, whereas those who came of political age fighting the establishment are less likely to share that perspective. On its face, Joe Biden should be more pro-Israel than Bernie Sanders. The same should hold true when considering, for instance, Cory Booker and Elizabeth Warren.

These conclusions seems simple and correct enough, but stakeholders on all sides would be mistaken to take them at anything close to face value. The interaction of policies, personalities, and expectations is not an exact science. America alone does not determine the U.S.-Israel relationship, and it’s thus illogical to favor a candidate on the basis of what they have said about Israel.

In recent weeks, IfNotNow has been following Democratic candidates on the campaign trail and asking them if they support ending the Israeli occupation in the West Bank and East Jerusalem. IfNotNow is a group of mostly young anti-occupation American Jews who first organized in the summer of 2014 in response to Operation Protective Edge. The group, which takes no position on Zionism, BDS, and the two-state solution, initially targeted American Jewish organizations who they believed were supporting the occupation. It seems they have now turned their focus to the American political arena.

The responses of the candidates have mostly gone as expected, with IfNotNow lauding the frank anti-occupation responses of the progressives (Sanders and Warren) and criticizing the traditionalists who either hedged or also highlighted the role and responsibilities of the Palestinians (Biden, O’Rourke, and Booker). The odd case was Pete Buttigieg, a moderate who told IfNotNow activists that “the occupation has to end” without qualification.

The attention Israel has received in the campaign thus far is troubling to some. Democratic Majority for Israel, a group of more traditional pro-Israel Democrats, sent a memo to Democratic campaigns warning them of IfNotNow’s activities. This reflects a concern that candidates are locking themselves into anti-Israel foreign policy positions.

But both sides here are probably overvaluing the words of candidates on the campaign trail and thus missing a crucial point: the identity of Israel’s prime minister in January 2021 is unknown. How Israel’s reaction to a potential shift in tone or policy will be a determinative factor in the future of the relationship. It is the combination of American and Israeli leaders and policies, and the mutual expectations they create, that matters.

To illustrate this point in less theoretical terms, let’s imagine Joe Biden being elected president of the United States and Benjamin Netanyahu remaining prime minister of Israel. On the surface, from both “pro” and “anti” Israel perspectives, a Democrat positively predisposed toward Israel has been elected. But this in itself says nothing about how he will react to potentially provocative actions by the Israeli government, such as settlement construction announcements. What we could reasonably say is that, as a self-described friend of Israel, Biden would expect to be treated respectfully and fairly by any Israeli government – setting up the potential for him to be distinctly embarrassed by Israeli actions, which could then trigger a backlash that permeates the rest of the presidency.

Does that sound vaguely familiar? That’s probably because something resembling this exact scenario happened in 2010.

What if Bernie Sanders, Elizabeth Warren, or Pete Buttigieg is elected? There is certainly a case to be made that American policy toward Israel will be considerably tougher. But again, we can’t say for sure until we know the policies and behaviors of the future Israeli government. A moderate Israeli government that appears serious about the two-state solution could potentially weaken the argument for a strong American stance against the occupation. A hardline right-wing government in Israel may not appear as jarring to progressives who don’t expect any better of Israel. To Sanders and his foreign policy advisor, Matt Duss, a newly issued Israeli government tender for settlement construction in Har Homa may have a here they go again ring to it.

It is not hard to imagine counterintuitive scenarios such as the ones above. They point to a conclusion that should be obvious: the U.S. does not dictate all the terms of the U.S.-Israel relationship. At the end of the day, what a candidate pledges on Israel before an election won’t mean much without knowing the unknowable: who will lead Israel and how will we react to them?