Give George Mitchell points for perseverance, at least. Last year the attempt by President Obama's Middle East envoy to relaunch Israeli-Palestinian peace talks, with an ambitious two-year deadline, was an embarrassing flop. Neither Israelis nor Palestinians showed much interest in new negotiations. As the world watched, Israeli Prime Minister Binyamin Netanyahu forced the administration to retreat from its demand for a complete freeze on settlement building, while Saudi King Abdullah directly rebuffed Obama after he traveled to Riyadh to ask for a gesture to Israel.

So what is Mitchell's plan for 2010? A "comprehensive peace in the region," he said last week, "is the objective set forth by the president and the secretary of state." "The way to move forward," he told PBS's Charlie Rose, "is an Israeli-Palestinian agreement, Israel and Syria, Israel and Lebanon, and full implementation of the Arab peace initiative," in which every state in the Arab League would recognize Israel. This negotiation, he added "should last not more than two years" and "personally I think it can be done in a shorter period of time."

One way of interpreting this is that Mitchell and his boss have refused to be deterred by the resistance they've run into. Another is that they have learned nothing from their mistake-ridden first year. Either way, the administration has once again publicly set for itself a hugely ambitious goal in a part of the world where diplomatic failure is punished harshly.

Mitchell's sang-froid is not completely unfounded. The administration's opening offensive did succeed in getting Netanyahu to commit, for the first time, to Palestinian statehood, and to a partial, 10-month settlement freeze outside Jerusalem. An even bigger achievement, begun under the Bush administration, has been the professionalization of Palestinian security forces in the West Bank, which has largely prevented violence and allowed Israel to pull back some troops and roadblocks. That, along with a rebound of economic activity, is the beginning of what could be the most promising development in decades: a serious, Palestinian-led effort to build the institutions of a viable state from the ground up.

The fundamental obstacles that tripped up Mitchell nevertheless remain. Netanyahu's vision of Palestinian statehood is a non-starter: It rules out shared sovereignty in Jerusalem, for example. Mahmoud Abbas, the weak and aging Palestinian leader in the West Bank, has already rejected a far more generous offer from Netanyahu's predecessor. Arab states, which spent last year waiting for Obama to crack down on Israel, have recently begun nudging Abbas to resume negotiations. But they still aren't willing to take political risks of their own.

Netanyahu's ambassador in Washington, Michael Oren, told me that Israel doesn't like Mitchell's two-year timetable, which he said "is unrealistic and might prove counterproductive." "We know from our experience that state-making takes a long time," he said.

Mitchell's response to such objections is to recall his brokering of the 1998 Irish peace accord -- which, he pointed out to Rose, took him just under two years. "One thing I learned in Northern Ireland is, you don't take the first no as a final answer," he said.

Fair enough. But Mitchell has a way of brushing off the lessons his many predecessors acquired the hard way. For instance: Breakthroughs in the Middle East don't start with the United States but with the parties themselves. And: Big, ambitious attempts to settle the whole conflict in one set-piece negotiation not only fail but often are followed by violence -- such as the Palestinian uprising after Bill Clinton's Camp David summit, and the war in Gaza after George W. Bush's Annapolis process.

Another lesson Mitchell says he learned from the Irish is that "timing is everything in life. What constantly happens is when one side is ready, the other side is not." At the moment, the United States is ready in the Middle East -- something that hasn't always been true. But it's not clear that any of the other parties -- Palestinian, Israeli or Arab -- are. As Mitchell himself put it, "what we have to do is find the formula that gets them both ready at the same time on all these fronts." If he does that in two years, he'll prove me and most other Middle East watchers wrong.