By Jeremy Bowen
BBC Middle East editor
Mr Obama urged Israel's critics to accept the state's legitimacy
President Barack Obama is good at making speeches. His best ones create a powerfully seductive political mood that change is coming, not just at home but in the way the United States does business with the rest of the world.
His address to the UN General Assembly showed, once again, not just his rhetorical skill but his understanding of the forces that drive international affairs.
But his speeches cannot answer the biggest question about Mr Obama's leadership: can he translate fine words into concrete actions?
So far he has not managed it in the Middle East. No reasonable person should expect a solution inside his first year.
But Mr Obama has suffered because of the expectations that his own words have aroused.
He made a speech aimed at Muslims around the world in Cairo in June that for a while induced a state of near euphoria among observers who had been fierce critics of the foreign policy of President George W Bush.
Mr Obama will be criticised if his gamble produces no result - but it is worth taking
At the UN General Assembly he felt it necessary to tell his audience that he was not naive about how hard it would be to make peace in the Middle East.
That was a response to accusations that it was unrealistic to ask Israel publicly to freeze the development of Jewish settlements in the occupied Palestinian territories, which are illegal under international law. Israel has refused.
Undeterred, at the UN he returned to some of the big themes that he raised in his Cairo speech.
Once again, he emphasised the commitment of the United States to Israel's security, and urged its critics to accept its legitimacy.
But he also repeated his support for Palestinian aspirations for freedom. And he repeated that America "does not accept the legitimacy of continued Israeli settlements".
Mr Obama told Israelis and Paestinian leaders to get on with making peace
The reality with which he is grappling though is that Israel continues to expand its settlements.
Arab countries have not come up with goodwill gestures towards Israel, which were also on Mr Obama's wish list.
Months of what he described as steady and aggressive American diplomacy have produced only a brief, cold public handshake at the Waldorf Astoria hotel in Manhattan between Palestinian President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu.
At that event, which Mr Obama had envisaged as a mini summit before it was downgraded to a photo opportunity, the US president sounded impatient, even exasperated as he called on them both to put aside the bitterness of history and to get on with making peace.
Mr Obama's Middle East envoy, George Mitchell, has been suggesting that a settlement freeze was never an American precondition for talks.
But both Mr Obama and his Secretary of State Hillary Clinton stated unequivocally that Israel should stop building for Jews in the occupied Palestinian territories.
Palestinians say they will not negotiate with Israel until it freezes settlements
Mr Netanyahu's refusal to do as he was asked has been an embarrassing, even humiliating reminder of the limits of America's influence over Israel, a close ally which receives billions of dollars of US military aid and lashings of political support.
Mr Obama's response has been to spell out to the UN General Assembly that negotiations on the toughest issues should be re-launched without preconditions.
He wants agreement on security for Israelis and Palestinians; the borders of Israel and a future Palestine; the fate of refugees and the future of Jerusalem.
It is another ambitious move. Mr Abbas has stated that he will not negotiate with Israel until it freezes settlements.
Does that mean he would allow negotiations with an American intermediary?
And it is not at all clear that Mr Netanyahu wants to talk about the future of Jerusalem, among other contentious issues. To do so could result in resignations from his coalition government.
By calling on them to settle what are known as the permanent status issues Mr Obama is putting pressure on both sides. It is going to be hard for them to turn him down, but they might.
If they do start to talk the Americans will have to make sure that process and procedure do not become substitutes for progress. They say they realise that.
Mr Obama will be criticised if his gamble produces no result. But it is worth taking.
The only way for the two sides to make peace is to settle the big issues between them. They need to try.