Israel must recognize the legitimacy of all forms of Judaism, emphatically including Reform and Conservative Judaism, or it will alienate those movements, the just-returned Israeli ambassador to the United States, Michael Oren, said in an interview.

Oren, who in October ended a four-year stint as Israel’s envoy in Washington, DC, said it was all well and good for Israel to describe itself as “the nation-state of the Jewish people” — a formulation, now routinely used by Prime Minister Benjamin Netanyahu, which Oren said was adopted on his recommendation — but “we’ve got to stand behind it. Now we’ve accepted the formula, let’s live up to it.”

In an interview with The Times of Israel, Oren warned that “if Israel does not work to make itself the nation-state of all the Jewish people, and be truly pluralistic and open about this, then we risk losing these people.”

The former ambassador was commenting on the current state of US Jewry and its relationship with Israel.

Asked, first, about the impact of the settlement enterprise on Israeli-Diaspora ties, he said certain Jews were troubled by the expansion of settlements, and others were “dissatisfied we’re not building more and faster… I had as much opposition from the American Jewish right as I did from the American Jewish left,” he added, “for being in favor of the two-state solution. For effecting the moratorium [on settlement building] in 2010. For prisoner releases.”

Oren described the American Jewish community as being “similar to what many physicists say is occurring in the universe — that it’s expanding and contracting at the same time. So the American community — read the Pew Report — they’re contracting through intermarriage and assimilation. However, at the same time, there’s a strong kernel of the American Jewish community, not just Orthodox, but also Jews who’ve gone on Birthright, who are more connected Jewishly and more connected to Israel, and that’s expanding… So if you look down the road, 20 or 30 years from now, the American Jewish community may be smaller, but it could also be more Jewishly identified and more connected to Israel.”

At the same time, he warned, “on the constriction side, you have not only Jews who are disaffected because of Israeli policies, but also because the State of Israel doesn’t recognize Reform and Conservative Judaism.”

He said the only thing that all the rabbis he met with agreed upon — be they Reform, Conservative or Orthodox — was their opposition to the Israeli Chief Rabbinate, which doesn’t recognize even most US Orthodox conversions today.

More broadly, he said, Israel needed “to recognize all forms of Judaism. We have to recognize the roles of those movements in Judaism within different life-cycle events in Israeli life. We risk alienating them. The amazing thing about the Reform movement is that, after so many years of not being recognized by the State of Israel, they remain so pro-Israeli. That to me is extraordinary.”

He could not be fully confident, he said, that this would last forever. “I‘ll sit with American Jewish Reform and Conservative leaders who care passionately about Israel,” Oren said. “But they’ll say to you: I can’t tell you how hurtful it is that the State of Israel doesn’t recognize my form of Judaism. It is the worst pain when you say something like that. It’s something we have to address as a society if we are to remain the nation-state of the Jewish people.”

The ex-ambassador’s comments came two weeks after Netanyahu became the first prime minister to address the Union for Reform Judaism’s biennial US gathering. In a speech via satellite to the event in San Diego, Netanyahu said “Israel is, and it must continue to be, the homeland of the entire Jewish people, the entire Jewish people. That’s the place where all Jews — including Reform Jews — experience nothing less than ‘audacious hospitality.’” He added that he was “committed to doing everything in my power to ensure that all Jews feel connected to Israel and to each other.”

The Times of Israel’s full interview with Michael Oren will appear later this week.