U.S. presidents of every political stripe have plunged into the Israeli-Palestinian peace process, only to be humbled at the end.

Now Donald Trump is trying his hand. He landed in Jerusalem on Monday, after two days in Saudi Arabia, having declared his eagerness to make “the ultimate deal” on Israeli-Palestinian peace. Only days ago, he told Palestinian leader Mahmoud Abbas that such a deal was “something I think is, frankly, maybe not as difficult as people have thought over the years.”

Only someone totally unversed in Middle East history and realities could spout such pap.

So here is the advice I hope the smarter members of his traveling team are trying to spoon feed the president on the Israel-Palestine part of his journey in the fervent hope he listens — and doesn’t go rogue.

First, tone down the messianic predictions of peace in our time. This should be a learning trip for Trump if he is willing to listen and observe carefully, which is not his forte.

Neither Israeli nor Palestinian leaders are willing or able to make the compromises needed to get serious peace talks back on track. Moreover, the time for a two-state solution may have already passed.

Neither Israeli Prime Minister Benjamin Netanyahu nor his far-right government is willing any longer to entertain the idea of a viable two-state solution, meaning a demilitarized Palestinian state alongside Israel. Netanyahu’s endorsement of ever more rapid Jewish settlement of the West Bank makes this very clear.

Even were a different Israeli government in place, Abbas is too weak and the Palestinians are too divided to make the necessary compromises. And the chaos in the region rules out any prospect of creating another weak (Palestinian) Arab state in the foreseeable future.

Trump has talked glibly about the possibility of a “one-state solution” — which would result in a largely disenfranchised Arab majority within a Greater Israel. Clearly, the president had no grasp of the risks that idea presented to the survival of the Jewish state. If only he were interested, this trip would present an opportunity for him to examine what this idea would mean.

Second, don’t let the pomp and flattery that the Saudis heaped upon you fool you into believing we have entered a new Mideast era.

The sub-rosa alliance that has developed between Sunni Gulf Arab states and Israel to counter Iranian mischief in the region may produce some modest normalization with Israel, like permitting Israeli businesses to open branches in Gulf states, or Israeli planes to overfly some Arab airspace.

But even such small steps would require that Israel’s government make reciprocal gestures. Prime among them would be the freezing of Jewish settlements on the occupied West Bank outside of settlement blocs likely to remain part of Israel under a two-state solution. Such an Israeli gesture is highly unlikely.

Third, dynastic politics may be popular in the White House and in Riyadh, but it won’t produce Mideast peace.

It’s all well and good for the Saudi monarch to appoint his young pilot son as ambassador to Washington and make another son defense minister. But Trump’s appointment of first son-in-law Jared Kushner and the Trump organization’s top lawyer as chief Mideast peace makers won’t cut it.

No peace process will revive unless the president himself masters a minimum of details, for which he needs expert advisers. It’s no accident that the only U.S. president who produced a Mideast peace treaty — between Israel and Egypt — was Jimmy Carter, who studied the history and toured the terrain. He understood the Mideast’s religious conflicts in his mind, gut, and heart.

Fourth, during your visit to Israel, do not — repeat, do not — pledge to move the U.S. embassy from Tel Aviv to Jerusalem, as you promised on the campaign trail. Arab states, along with Palestinians and most Israelis, would see this move as a signal that Washington accepted Israel’s claim to all Jerusalem, including the Arab East of the city. In other words, that East Jerusalem was not subject to peace negotiations.

Do not doubt the explosive power of the Jerusalem issue. An announcement of an impending embassy move would end any putative peace process before it began. It would provoke violence in the West Bank and within the Arab world, and undermine the nascent ties between Israel and Gulf Arabs.

Some careless words, an errant tweet, could turn this Mideast trip into a political disaster.

So fifth, please stay on message, Mr. President, until you leave the Mideast behind.

Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer.