The prophets have spoken, and it is time to retreat from Babylon. Or so says the Union for Reform Judaism, speaking for the largest branch of American Judaism. The Union's "prophetic mission and God's call to us to be a 'light to the nations'" has, in its own telling, compelled it to demand "a clear exit strategy with specific goals for troop withdrawal" from Iraq.

The task of halting the Union's foray into politics has fallen mostly to the Republican Jewish Coalition, which, unlike the Union, bills itself for what it is: a partisan organization. As a result of all this, President Bush, already bogged down in Iraq's sectarian divisions, finds himself ensnared in a religious feud right here at home. In a major address on Iraq last week, the president was reduced to playing the Israel card, pleading with its supporters to acknowledge that "Israel's long-term survival depends upon the spread of democracy in the Middle East."

In one sense at least, the Union's outburst amounts to something more than the everyday pollution of public discourse. Recall that on the eve of the invasion of Iraq, the claim that the Jewish state and its American co-religionists were manufacturing war had become canonical in certain quarters. From the right, Robert Novak described the conflict as "Sharon's war," while from the opposite end of the spectrum, The Nation reported that the war's promoters subscribed to "articles of faith that effectively hold there is no difference between U.S. and Israeli national security interests."

Never mind that Israeli officials were lukewarm about the war from the outset, being far more concerned with the threat from Iran. Never mind, too, that American Jews were more likely to be among the war's most vocal opponents than among its boosters. (A Yeshiva University poll earlier this year found that two-thirds of American Jews disapprove of the U.S. enterprise in Iraq). The Union's stand demolishes the canard that American Jews cannot distinguish between Israel's interests and their own.

Judging by the Union's vocal opposition to the war, the problem, if anything, appears to be the reverse: What is "good for the Jews" seems to concern the organization less than what is good for American liberalism. A premature withdrawal from Iraq would be devastating to the cause of the Jewish state. That observation does not reflect the motives for having gone to war, but simply the outcome of abandoning a fellow democracy without condition and regardless of consequence -- and the obvious consequence would be Iraq's transformation into a den of terror. None of this seems to have made an impression on the reform Jewish organization.

The Union, which "came to these views based on Jewish teachings on war" and likens itself to "the rabbis of the Talmud," has no claim to heightened moral awareness. Not only because it twists the words of those very rabbis (as with any religious text, the Talmud offers ammunition to multiple points of view, invoked to defend everything from Israel's invasion of Lebanon to the "axis of evil" formulation). And not only because the Union's intrusion into the public square comes from an organization that claims to be in the midst of an "ongoing defense of the wall of separation between church and state." No, the real problem is that the Union grounds its arguments squarely in the traditions of secular humanism, and then purposefully conflates them with the traditions of religious Judaism.

True, the worldly admonition tikkun olam -- repair the world -- is one of Judaism's signatures. But the Union isn't about repairing the world. Is it really necessary, after all, to point out that its insistence on a U.S. withdrawal does nothing to further the Union's call to "support the democratically elected Iraqi government"? Or that the "international community" that it invokes at every turn would sooner the Union's members no longer existed? Or that the biblical injunction to "not stand idly by the blood of your neighbor," one among many kernels of Jewish law the Union ostentatiously cites in defense of its Iraq position, means not abandoning Iraq to its fate?

Apparently so, because for all its confusions, the Union really does amount to an authentic expression of the political inclinations that define American Judaism today. As evinced by the Union's position on Iraq, those inclinations defy easy logic. The American Jewish community's attachment to the political left goes beyond obstinacy -- to the point of running counter to the very requirements of that same community. Hence, when asked to choose between the security of Jews, on the one hand, and clichés about social equality and inadequate domestic expenditures, on the other, Reform Jewish leaders have put what they presume to be the secular equivalent to Judaism above the interests of Judaism itself. The Union for Reform Judaism stands for many causes. It's no longer so clear that Jews count among them.

Mr. Kaplan is a senior editor at the New Republic.