Liberal Zionism is among the most nebulous nouns in the debate that surrounds the Israeli-Palestinian conflict and where American Jewish progressives ought to stand. For one thing, who are the Israeli counterparts? Is it the decidedly left-wing Meretz party, or the more traditional Labor party, or even the nominally centrist Hatnuah and Yesh Atid parties? Or perhaps it is an ethos that transcends party lines?

There is no answer to that question, other than that liberal Zionists have been redefining “the big tent” for years with their characteristically robust support for the two-state solution and opposition to settlement construction. It’s fair to wager that it’s a younger movement, more inclined to question Israeli policies than their parents and right-wing friends. While growing, it will likely remain a minority for years to come. Therefore, how this movement responds to the incipient Boycott Divestment Sanctions (BDS) movement against Israel will be crucial in its forming a mainstream identity acceptable to middle-aged, older, and right-leaning American Jews.

Recently, the Conference of Major American Jewish Organizations rejected the application of J Street, the largest liberal Zionist organization in the United States, to become a member. Numerous reasons were cited by commentators from across the Zionist spectrum. But what J Street’s active and passive supporters heard was a distinctive insult: you’re not pro-Israel enough.

It was therefore tempting for some to interpret the rejection as an opportunity to finally give up on integration within the broader Jewish community. J Street, and other liberal Zionists, have chosen to keep going. This is the right decision.

Larry Derfner, a leftist commentator who supports BDS, has averred that J Street has, “begun to act in concert with unambiguously right-wing Zionist organizations such as AIPAC and StandWithUs in their efforts to kill the Boycott, Divestment and Sanctions movement while offering no alternative for ending the occupation”.

J Street’s offense? Their student affiliate at the University of Washington joined other pro-Israel organizations in opposing a student government resolution that would’ve recommended the school divest from Israel.

Last week, the Presbyterian Church’s General Assembly began considering a boycott resolution (it has since passed, narrowly). This presented a particularly perilous situation for liberal Zionists: the resolution was focused on three American companies that do business in the settlements, it explicitly backed a two-state solution, and distanced itself from the formal BDS movement—by name no less. Some liberal Zionists have supported similar measures. Peter Beinart, a prominent liberal Zionist and author of “The Crisis of Zionism,” has often talked about “Zionist BDS,” at its core a boycott of all products manufactured across the Green Line.

As a personal decision, such a boycott cannot be condemned as pernicious. Many Israelis, including veterans of the Six Day War which resulted in the capture of the West Bank and East Jerusalem, believe the settlements are inimical to Israel’s self-interest. But at an institutional level, it can hardly be seen as anything but part of a “wave” of BDS successes. Once again, liberal Zionists made the right decision and opposed the Presbyterian boycott resolution.

Rachel Lerner, speaking on behalf of J Street, emphatically stated that, “The self-determination of one people cannot be advanced by undermining the self-determination of another,” and that the preceding campaign in support of the resolution had been nothing short of “disturbing.”

BDS, a movement that Norman Finklestein of “Holocaust Industry” fame finds too risqué, lends the perfect opportunity for liberal Zionists to take up the mantle of prudence. In order to do this, liberal Zionists must warn of the incoming international isolation of Israel, which continues to entrench herself in the West Bank, while fighting this isolation tooth-and-nail. This may seem contradictory to some, but not to those who love Israel to the extent they want it to exist, as a Jewish state, for their grandchildren and on.

Liberal Zionists should continue the fight against BDS, because what happened in Washington State and at the Presbyterian Church General Assembly sent a clear message to the majority of the Conference of Presidents, and other opponents of liberal Zionism in the pro-Israel camp: when the delegitimization circus comes to town, liberal Zionists will be on the front lines with you; we’re no more likely to abandon Israel than you are.