The Obama administration's inability to bring about a settlement between Israelis and Palestinians has prompted a search for new ideas. The latest was voiced most confidently this week by The Economist, the British news magazine.

In a leader titled Please, not again, the publication warned of a terrible conflict in the Middle East unless new urgency was injected into Israeli-Palestinian peace negotiations to starve regional rejectionists of their oxygen. But to do so, President Barack Obama had to legislate, not mediate: "America has clung too long to the dogma that direct talks between Israel and the Palestinians are the way forward," The Economist argued. "The recent history proves that the extremists on each side are too strong for timid local leaders to make the necessary compromises alone. It is time for the world to agree on a settlement and impose it on the feuding parties."

In fact, the proposition is not new. Years ago, the International Crisis Group also recommended that Washington define an endgame, based on the well-established principles that had emerged from countless rounds of negotiations, then push the parties towards it. With step-by-step measures creating space for both sides to escape their obligations, and no confidence whatsoever from Palestinians or Israelis in "confidence building" methods, the argument went, it was time for the United States to go all the way and make its preferences known, instead of relying on the parties to define outcomes.

The idea may sound as good as any other in a "peace process" that has been short on peace and increasingly bankrupt in terms of process. Certainly, it emanates from a legitimate grievance that the approach of the past decade and a half, that of making gradual headway through mutual concessions toward a final accord, has apparently run its course. However, there are serious difficulties with The Economist's proposal, regardless of the necessity of a settlement.

To begin with, the proposal comes close to violating a cardinal rule of diplomacy: never announce your final position, as this may leave you with little room to manoeuvre later. Defenders of this course, however, would argue that Washington only needs to pronounce what it views as the broad guidelines of an accord, the consequence of two decades of negotiations. Yet the former president Bill Clinton already did that in 2000 with his "parameters" before leaving office. While Mr Obama might seek to re-energise these, it is not immediately evident how doing so would break the current deadlock.

The reason for the deadlock is structural. In Israel and the Palestinian areas, political forces that are either lukewarm towards or opposed to a settlement along the lines of the post-Oslo consensus are in a position to block progress. That includes Israel's prime minister, Benjamin Netanyahu, who may appear less extreme than many of his coalition partners, but also has made a career of undermining Oslo and its aftermath. As for Hamas, its principal preoccupation today appears to be to take control of the Palestinian national movement, so that any advance that strengthens the rival Fatah movement is anathema.

This highlights another problem with any American decision to impose an endgame in Palestinian-Israeli negotiations. Once the Obama administration declares itself in favour of a specific plan, the plan itself, rather than a settlement, risks becoming the focal point of debate and disputation. Those hostile to a settlement will do everything possible to rally public suspicion against the plan and avoid making the mutual concessions demanded of the Palestinians and Israelis. Very likely, they will succeed.

Assuming that Mr Obama goes ahead with the strategy anyway, where might this lead? The Economist maintains: "America must ride herd, providing reassurance and exerting pressure on both sides as required." But by adopting such an approach in a time of deep polarisation on the Palestinian and Israeli sides, the president will quite possibly end up relying more on pressure than reassurances. In other words, Mr Obama will have to ensure that he can and will go all the way in browbeating the parties to embrace his optimal deal.

But how likely is that? Last year the president stepped away from a confrontation with Mr Netanyahu over settlements. Mr Obama is now facing an unfriendly Republican majority in the House of Representatives and a divided Senate, both of which will almost certainly resist if he decides to tighten the screws on Israel. If Mr Netanyahu refuses to play ball, the White House's strongest card is to withhold credit guarantees and military aid to Israel. But the president has no stomach for that fight in Congress, especially at a time when Iran is seen by many in Washington as the real threat in the Middle East. For Mr Obama, tough love is a non-starter.

Mr Obama's best bet today is to garner international support for his own settlement parameters, without actually coming out and declaring what these are. Most countries are fed up with the stalemate between Israel and the Palestinians, and are increasingly exasperated with Israel's refusal to surrender anything substantial or even symbolic in negotiations. The president can use this as leverage, but his latitude to implement a final push toward peace can only seriously be contemplated once he has a fresh mandate, for example if he is re-elected. This will not remove structural impediments to talks, nor is it guaranteed of success. But for now Mr Obama has no other choice.

The danger in pushing too aggressively for a final settlement is that if Mr Obama fails again, he may be left with no Plan C. Having tried everything, the US may end up with nothing left to offer, fatally discrediting itself in the Middle East. Tying oneself to the lame horse of Palestinian-Israeli accomplishment can do that to you.