Americans should rejoice at the promised resumption of talks between the Israelis and the Palestinians toward peace in the Middle East.

The danger inherent in the situation, for the region and the world, makes it urgent for President Barack Obama to make good on his promise to address the problem. So far, the efforts of the U.S. special envoy, former Sen. George J. Mitchell, have led to little, although not for want of his trying.

The meetings that may begin soon are indirect, so-called proximity talks, with the Israelis and the Palestinians not meeting directly but sitting separately, while Mr. Mitchell or another envoy carries statements of position between them. The U.S. role would be that of mediator.

The proximity mechanism, as opposed to direct talks, is the first potential flaw. The difference between face-to-face meetings and indirect negotiations is obvious in terms of probability of success, although they could be a start if direct talks have been ruled out for the moment because of the intense hostility between the two groups.

The second problem is the Palestinians remain split among themselves, between Fatah, which will be part of the talks, and Hamas, which will not.

The third problem is that, on the key issue of Israeli settlements in the West Bank, some land of which would be Palestinian if a two-state solution were reached, the government of Israeli Prime Minister Benjamin Netanyahu is pushing ahead with expanding Israeli housing there, not freezing it, as U.S. administrations have asked.

Israel announced Monday that it would construct 112 housing units in the West Bank. The next day it said it would build 1,600 units in occupied East Jerusalem, which further infuriated the Palestinians because they want their capital to be there.

The fourth problem is Israel and the United States have inserted the issue of Iran's nuclear intentions into the negotiations. Prospects for unsnarling that tangled problem are not bright, given Washington's ambivalent position on economic sanctions.

Vice President Joseph Biden visited the Middle East this week to try to give the talks a strong start. But some of his remarks may have created a fifth problem -- compromising the U.S. role as mediator by stating his government's "absolute, total, unvarnished commitment to Israel's security."

That may be an accurate statement of the Obama administration's position, but it won't inspire Palestinian confidence in the United States as an evenhanded broker, even though Mr. Biden said later that Palestinians deserve an independent state that is "viable and contiguous." Israel's announcement of the construction in Jerusalem during the vice president's visit constituted a slap in his face.

Despite such sparks this week, the hope is that the pressing need for talks will be enough to carry them over these hurdles. Sustained negotiations are essential in the quest for Middle East peace.

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