Reading Rabbi Julie Schonfeld’s recent defense of Conservative Judaism’s ban on rabbis performing intermarriages, my primary sentiment was one of sadness. Why, though? It was not that I disagreed with her; on the contrary, I echo many of her sentiments and agree with her bottom line that performing mixed-faith marriages is a red line that the Conservative movement ought not countenance its rabbis crossing — which rabbis with ties to the Conservative movement, like Amichai Lau-Lavie and Rolando Matalon, have recently pledged to do.

In part, I realized, the sadness stemmed from the fresh reminder that to make her argument, Schonfeld relied on a vocabulary that decades ago drew me to the movement, but that it has long since abandoned.

Schonfeld based her argument on the fundamental rationale behind the limitations of Halacha, Jewish law. “Judaism, as a continuous tradition for 3,000 years,” she wrote, “promotes a highly counter-cultural idea in contemporary society in that it finds special opportunity for spiritual and moral growth in the maintenance and appreciation of boundaries -– whether around time, food, consumption, moral conduct and even relationships.” What it means to be a Jew, she believes Judaism argues, is to live and grow within those “bounded” spaces.

She’s absolutely right. The problem, though, is that the history of the very movement that she helps to lead has long undermined that argument. The movement paved the way to sanctioning intermarriage decades ago, long before anyone even contemplated doing so.

Fire on Shabbat is explicitly prohibited by the Torah; yet as long as cars use gasoline, operating them will involve combustion. Nevertheless, succumbing to urban sprawl and its attendant demographic pressures, in 1950 the Conservative movement sanctioned driving on Shabbat. (Some 53 years later, Ismar Schorsch, then chancellor of the Jewish Theological Seminary, declared that decision “a mistake”.) Similarly, eating fish in a nonkosher restaurant obviously means consuming food made with utensils and pots that have just been used for nonkosher meat, but again, seeking to accommodate its members’ shifting social networks, the movement ruled in 1952: “Fish dinners in nonkosher eating places shall not be construed as a violation of the dietary laws.”

In neither case was there a serious halachic argument to be made; instead, there was social pressure. Conservative Judaism bet that by moving the line, it could keep its members within the boundaries. That bet has proved dead wrong.

As much as intermarriage is now being portrayed as the ultimate line in the sand, one could make the argument that intermarriage is actually less halachically problematic than same-sex marriage. But in May 2012, Conservative Judaism sanctioned those unions as well. (I am not taking a stand on gay marriage here; if anything, that issue has the most compelling moral justification of all the above-mentioned examples.)

The sum is thus greater than the whole of the parts. Driving, eating out, gay marriage and more: For more than half a century, the Conservative movement has been — with apologies to Rodgers & Hammerstein –- “just a movement that can’t say no.”

Schonfeld is keenly aware of the movement’s halachic history. Therefore, she added an additional element in a sentence about those “bounded spaces,” which reads, “Those boundaries include the reservation of Jewish rituals that are the explicit performance of Jewish commitments to Jews.” Thus, the issue isn’t Halacha, per se, it’s that the movement will not condone Jewish rituals that involve non-Jews.

But even that, this time with apologies to Gershwin, “ain’t necessarily so.” In March, the United Synagogue of Conservative Judaism General Assembly passed a resolution allowing synagogues to accept non-Jews as members. Synagogue membership is not technically a ritual, true, but that decision was already an indication that religious boundaries between being “in” the community and “out” were not holding. If a person can be a member of a religious community, why can that person not participate in its rituals?

No less saddening, though, was the fact that glaringly missing from Schonfeld’s column is any mention of the next dramatic change that obviously lies just around the bend. Once the Conservative movement sanctions intermarriage, as it almost certainly will, patrilineal descent will invariably follow. Does anyone really believe that the movement can say, “Yes, one of our rabbis married you, but no, we don’t consider your children Jewish”? It was that entirely untenable position that led Reform Judaism to adopt patrilineality. Not that far off is the day when people whom Conservative Judaism calls Jews will not be able to marry Orthodox Jews or many Israelis.

And that, in turn, leads to the deepest reason for my sadness at reading Rabbi Schonfeld’s column. Back in the days when my colleagues and I were studying at the JTS, the notion that the Conservative movement would sanction intermarriage would have been dismissed as laughable. Same-sex marriage wasn’t even really on the agenda. The big issue in our day was the ordination of women, which many of us (myself included) passionately supported.

So here, bottom line, is the question that haunts me: Had we known back then where matters were headed, how many of us would have chosen to study where we did?

Daniel Gordis is the Koret Distinguished Fellow at Shalem College, in Jerusalem. His latest book, “Israel: A Concise History of a Nation Reborn,” just received the National Jewish Book Award as the 2016 Book of the Year. He is, with Peter Beinart, the co-host of the “Fault Lines” podcast.