Israel believes that President Trump — at least for now — will shrink from moving the American embassy to the capital at Jerusalem. That’s the report in the Israeli daily Haartetz. “Ask me in a month,” Mr. Trump himself told Reuters. “I want to see peace with Israel and the Palestinians,” he said. “There is no reason there’s not peace between Israel and the Palestinians — none whatsoever.”

Then again, too, there may be — our own policy in respect of Jerusalem. For two generations — or more — the geniuses at our State Department have clung to the idea that the question of Jerusalem is best treated as a matter for “final status” negotiations. It should have been the opposite, with recognition of Israel’s claims as not a final status matter but as a precondition for peace. By holding it out for final status talks, we have given the Palestinian Arabs an incentive to avoid settlement.

It’s hard to see how this logic is shifted by the president’s waffling on this head. His promise in respect of Jerusalem was so public, so clear that anything less than a reiteration of it invites the impression that he is backsliding. Particularly because there’s no legitimate source of countervailing pressure. By legitimate we mean constitutional. Congress, lawgiver of our Republic, has spoken on this matter, most famously in the Jerusalem Embassy Act, which passed Congress almost unanimously in 1995.

Now it is being reported that Mr. Trump is going to exercise the waiver of the law’s requirement to move the embassy, presumably to buy time to pursue yet another peace process, this one on a regional basis. It’s conceivable that he, master deal maker that he is, can do better than previous presidents. It’s dollars to donuts, though, that failing on the outset to step up on Jerusalem will only complicate that process.

Whether Israel is the most pressing problem facing the president is another question. It strikes us that Prime Minister Netanyahu has been doing a fine job at standing his ground without an American president getting in between him and Israel’s adversaries. Mr. Netanyahu is, after all, the only prime minister in the Middle East with a democratic mandate. Mr. Trump would do just as well to turn his own attention to, say, the tax bill here at home and tell Israel’s adversaries to address their concerns to the government in Jerusalem.