ISRAELIS AND PALESTINIANS have responded to the latest U.S.-backed peace process plan with a familiar tactic: saying “yes” while meaning “no.” On Sunday the government of Prime Minister Benjamin Netanyahu said it “welcomes . . . the call for direct negotiations between the parties” but “has some concerns.” In fact, officials say that Israel objects to the proposal’s focus on reaching an initial agreement on borders and security, as well as its accelerated timeline, under which a peace deal would be completed in one year. The Palestinian Liberation Organization leadership, similarly, said it found “a number of encouraging elements in the plan” but made clear it will not agree to its proviso that negotiations begin “without delay or preconditions.”

Here’s another way of putting it: Israel is ready to begin the direct talks proposed by the “Quartet,” the diplomatic amalgam made up of the United States, European Union, Russia and United Nations, but not to follow the plan it laid out. Palestinians, while more sanguine about that plan, aren’t willing to start the talks — unless, that is, Israel meets some preconditions, including a complete freeze on Jewish settlements outside its pre-1967 borders.

Of the two, the Palestinian stance is more objectionable, and not only because it prevents any process from going forward. By his own account, President Mahmoud Abbas’s hard-line stance on the settlement issue is unfounded: He has said more than once that he adopted it only because he felt obliged to match a similar demand by President Obama. Mr. Obama, however, has dropped that condition; and as the Palestinians know, the matter is purely symbolic — both sides agree that Israel will annex the Jerusalem neighborhoods and West Bank settlements where most of the building is going on. For example, during a previous round of negotiations, Mr. Abbas’s negotiators specifically agreed to Israeli annexation of the Jerusalem neighborhood of Gilo; yet an announcement of new construction there last week prompted theatrical denunciations by those same Palestinian officials, as well as criticism from the Quartet.

Mr. Abbas’s insistence on preconditions allows him to continue his separate campaign for recognition of Palestine by the United Nations: He is about to embark on a global tour in search of votes on the Security Council. His cynical obstructionism ought to be enough to persuade undecided governments, such as Colombia and Portugal, to withhold support — or at least to require that Mr. Abbas fully accept the Quartet’s initiative before they back his.

As for Mr. Netanyahu, he could ensure the derailment of the U.N. initiative were he to explicitly announce what he has already hinted at: that his government will negotiate borders for Palestine based on the 1967 lines, with swaps of territory. He could also curb West Bank settlement construction beyond Israel’s security fence. Why should he do this? Because Israel, as visiting Defense Secretary Leon Panetta said Monday, is becoming “increasingly isolated” by events in the Middle East. That may not have been a helpful comment for a senior U.S. official to make publicly; bad actors of all kinds could take the wrong cues from it. Yet it happens to be true — and Israel’s response should not be passivity.