But then, it is not the first time his presence in London has heralded a supposed breakthrough in the Middle East peace process.

Eleven years ago, it was no less a peacemaker than Tony Blair who claimed credit. In the warm aftermath of the Belfast Agreement, Mr Blair summoned Mr Netanyahu, during his first stint as Israel's leader, for talks with Yasser Arafat of the PLO.

The success of that and subsequent summits can be easily described.

Hundreds died in a second intifada, or uprising, including Israeli victims of the first Palestinian suicide bombings, and hundreds more in Israeli wars with Hizbollah and Hamas.

The number of settlers living in the West Bank has grown. One step forward, the Israeli pull-out from Gaza in 2005, was opposed so strongly by Mr Netanyahu that he resigned from the Israeli cabinet in protest - he was then finance minister.

Peace accords on the Israeli-Palestinian issue do not have a good record, and what has emerged from Mr Netanyahu's meetings in London this week is not even that: it is a deal to have talks about talks.

But if Mr Netanyahu and the Palestinian president, Mahmoud Abbas, do meet in New York next month, low expectations may just be an unexpected boon.

Neither man is in a strong position. Mr Netanyahu expresses self-confidence on the world stage, but even he will find it hard to face down Barack Obama, who has been firm on the issue of Israeli settlements and can hardly afford to back down so early in his presidency.

Mr Netanyahu has made pledges on not beginning new settlements, but they are a long way short of Palestinian demands. In particular, he has excluded East Jerusalem.

That has left Mr Abbas no choice but to reject negotiations, which he has made contingent on and end to new settlements altogether. He cannot appear weak, so long as his bitter rivals Hamas control Gaza.

He may also feel that Mr Obama's stance has given him the right to define his terms of engagement on the issue.

But Mr Abbas knows he will never have a better opportunity to go to the negotiating table. The tide of world opinion is on his side - and that, for once, includes the United States.

Meanwhile Hamas are positioning themselves ever more subtly as potential "partners for peace": they are suggesting some sort of land for peace deal, in line with the Saudi and Arab League-backed "Arab Peace Initiative", might be acceptable.

Mr Netanyahu rejects that initiative and may never do business with Hamas, but European leaders seem increasingly keen to do so.

That gives Mr Abbas the opportunity to do some business - to hold "talks about talks" - while providing the threat that if he does not find a way forward, there is an alternative spokesman for his people waiting in the wings.