This week, President Bush is expected to wink approval of a plan by Israeli Prime Minister Ariel Sharon that would start to dictate to Palestinians the land they can have and the land they can't.
Such a move by Mr. Bush would shatter the historic role of the United States as the primary Middle East mediator, as well as the necessary tradition of treating Palestinians as a peace partner.
To be sure, the Palestinians' elected leader, Yasser Arafat, has proven to be an unreliable peace-seeker and negotiator, partly because of his inability, perhaps even his unwillingness, to suppress militant groups such as Hamas that send suicide bombers into Israel. His inaction has left Israel little choice but to take unilateral moves to defend itself.
But even if parts of the plan proposed by Prime Minister Sharon work well, such as a pullout of Israeli troops and settlers from the Gaza Strip, Bush's blessing of it would only leave an impression among Palestinians and Arab nations that the US is all too willing to defer the creation of a Palestinian state.
Such a diplomatic retreat by Bush - who had pushed for a Palestinian state by 2005 - could be used by anti-US terrorists to rally even more Arab converts and make the US-led war on terrorism more difficult.
That possibility explains why the US and Israel have been conducting weeks of secret diplomacy leading up to Wednesday's meeting between Mr. Sharon and Bush at the White House to finalize an agreement.
Sharon knows a US president is most compliant before an election, and while the wording of Bush's approval may be subtle, Sharon's words have been blunt: "In the unilateral process, there is no Palestinian state," he told an Israeli newspaper. "This situation could continue for many years."
Besides rejecting that idea, Bush needs to specifically oppose the portion of the Sharon plan that would make about 15 percent of the West Bank offbounds for a Palestinian state and retain it as a permanent home for Israeli settlers. In effect, Sharon wants the US to say officially that a chunk of the land taken in the 1967 war can be annexed to Israel for all time. Simply backing Israel's removal of 7,500 Israeli settlers from Gaza, while leaving more than 200,000 of them on the West Bank, is hardly a deal for peace.
Sharon also wants the US to back the current configuration of the fence that's snaking through the West Bank, effectively taking land while also deterring suicide bombers. That creates even more "facts on the ground" that the US might deem to be off the table in future negotiations.
Sharon needs the semblance of US backing to get the plan approved by his Likud party and Cabinet, both of which contain right-wingers who want to annex all of the West Bank. Bush should back only the Gaza withdrawal, and revive his "road map" as the best way to bring about peace.