Later today Donald Trump is expected to make a largely symbolic but important gesture, recognizing Jerusalem as the capital of Israel — not as an international capital or shared capital or capital in flux or as any of the other fantasies anti-Israel types have harbored since 1967. The most consequential long-term benefit of the move is that it begins to undercut a myth that’s stood for years.

Palestinian leadership might have deluded their own people for decades, but there is no conceivable peace deal that includes a truly divided Jerusalem. Like the Right of Return, the notion that a part of Jerusalem proper will be handed over to an antagonistic government, much less the remnants of the PLO and their on-and-off political partners Hamas, is a fantasy. This is not a radical Likud position, it’s one of the few issues that all major political parties, left and right, agree on in Israel.

Jerusalem, after all, is not some concocted modern capital. The place itself is the affirmation of the Jewish claim on Israel. Consequently, the coming protests over Trump’s move are not merely about a city, they are about challenging the right of Israel to exist — a self-destructive position that most Palestinians still embrace. This isn’t new. There has been a destructive effort within the Muslim world — although it has been taken up by others, including the United Nations — to deny the religious and historic connection between the city and the Jews. Moving the embassy, even if it entails nothing more than hanging a sign on a new building, is a pushback against attack on an ally.

That is, if you still view Israel as a close ally. Most do. Over the past 30 years, in fact, politicians keep telling voters that an undivided Jerusalem is the capital of Israel then doing nothing about it once they’re elected — and not some of them, but virtually all of them.

Bill Clinton attacked George H.W. Bush for having “repeatedly challenged Israel’s sovereignty over a united Jerusalem” and promised to back “Jerusalem as the capital of the State of Israel.” In 1995, the Jerusalem Embassy Act passed overwhelmingly in both the House and Senate. The law funds the relocation of the American embassy from Tel Aviv to Jerusalem and recognizes the city as the “undivided” capital of Israel. Clinton balked. So George W. Bush attacked Clinton for failing to deliver and promised that he would “start the process” of moving the embassy “as soon as I’m sworn in.” He didn’t. Barack Obama, openly antagonistic towards Israel from very beginning, didn’t even bother with the fiction.

Every one of these presidents signed a waiver every six months postponing the legislation. And every one of them failed to bring about a peaceful end to the conflict or a Palestinian state, because every one of them had to deal with unrealistic stipulations from Palestinian leadership, which included a demand that Jerusalem proper be the capital of their new state.

In June, when the no one thought Trump would follow through on his promise, the Senate, including every Democrat who was there, voted to “prod” the president, as Politico characterized it, into moving the Israeli Embassy to Jerusalem. The Senate voted 90-0 on a resolution marking the 50th anniversary of Jerusalem’s reunification, calling on the “president and all United States officials to abide by” by the 1995 law and “all its provisions.”

Now that Trump is reportedly finally moving on the issue, a number of Democrats oppose the idea. New Jersey Sen. Cory Booker claims that the issue must be “part of a larger peace process.” Sen. Dianne Feinstein says the move will spark violence (in her letter, the California senator also argues that a Jewish politician’s act of visiting a holy site is itself a provocation, but that’s another story.) For some reason these people believe Israel should be the only sovereign nation in the world unable to name its own capital.

There is, I am sure, a good debate to be had about the friction a law like the Jerusalem Act creates between the executive and legislative branches. But now that the president has decided to move forward, what is the case for allowing theocrats and authoritarians to decide where the United States puts its embassies?

Palestinian leader Mahmoud Abbas has threatened the United States and Israel with repercussions. Hamas is calling for another Intifada. A number of the usual suspects, including several totalitarian states that ban Jews from their countries, have “warned” the United States that such a move would cross a “red line.” (Here’s a little secret; most of these governments are posturing and couldn’t care less where the U.S. embassy is.)

Many of the same people who lecture us to stand up to the authoritarianism in Russia or China argue that we should cave to threats of groups that subsidize jihadists and undermine American interests. Why do Booker, Feinstein, or the experts at the Brookings Institution believe that Hamas or Qatar should dictate where the United States puts its embassy? Yes, the move will generate widespread hand-wringing in the world, and there is a good possibility that there will be a new round of self-destructive violence among Palestinians. But if Arabs are willing to embrace extremism and violence because the United States no longer supports a delusion, perhaps the problem isn’t Israel?

Then again, though the chances of any real peace with the Palestinians is slim, maybe reality will start to set in.