Leading article: Hope of a better future for Israel and Palestine

Tzipi Livni offers cleaner politics at home and realism abroad

History casts a long shadow in the Middle East. Talk of new beginnings has a tendency to raise expectations higher than reality will bear. So we should greet the prospect of a new Prime Minister in Israel with the more modest judgement that Tzipi Livni was the best on offer in the bunch contesting the leadership of the ruling Kadima party, and probably the best hope for peace among all the Israeli politicians who will jockey for power in the country's next general election.

The outgoing Prime Minister, Ehud Olmert, was serious about the peace with the Palestinians, but his reputation had become too tarnished by repeated allegations of personal corruption and his disastrous handling of the invasion of Lebanon in 2006. It is much in Ms Livni's favour that, within the Israeli cabinet, she opposed military action from day two of the fighting, pointing out that the Israeli public had been led to expect something from the military campaign which it could not provide, and pressing Mr Olmert to move swiftly towards the diplomatic solution.

So it is a positive sign that her party voted for her and not for her main rival, Shaul Mofaz, a former defence minister and chief of staff of theIsraeli army, who has made much more hawkish noises about the Palestinians and even threatened to attack Iran. Ms Livni is, unlike so many Israeli leaders in the past, not a general. But, given how little former generals have managed to achieve, that should not count against her.

Yet if she is far more committed to the peace process than Benjamin Netanyahu, leader of the right-wing Likud party, she is no push-over.Political reality may have led her on a personalpolitical journey from her family roots in right-wing Zionism to the centre ground. And she may have presented herself, in contrast to Mr Olmert, as Mrs Clean and the candidate for change, but she does draw lines in the sand. She refuses to accept even the token admission of Palestinian refugees to Israel envisaged in the 2000 Camp David talks. She was openly critical of Mr Olmert's decision to begin talks with Syria without Damascus first "ending its support for terror". And she has hawkish reflexes on Iran. But as foreign minister she has been both committed to, and deeply involved in, negotiations with themoderate Palestinian leadership of President Mahmoud Abbas, knowing full well these could end in the handover of much of the West Bank so long as that guaranteed an end to the conflict.

Her first task, however, is to form a government. She has just 42 days to do that, and thepolitics of coalition mean she must win somesupport from one of the small extremist parties which hold the balance of power in Israeli politics. The obvious one of these, the ultra-Orthodox Shas party, wants higher child allowances for the large families that make up its support base and a pledge that there will be no negotiations on the future of Jerusalem.

In the past, Ms Livni has hinted that she is not prepared to make random concessions to every interest group; indeed, she wants to break with the wheeler-dealing tradition of Israeli politics and restore public trust in the political process. She now has to strike a delicate balance between doing that and ensuring she can form an administration which will last long enough to present some serious progress on peace to the Israeli electorate at the next election in 18 months' time.

That is not long. Israel's controversial security wall may have stopped the suicide bombs for the time being, but she must not be lulled into thinking she has the luxury of time.