Three faiths laying claim to the holy city of Jerusalem begin to think the unthinkable

Medieval cartographers used to draw the holy city of Jerusalem at the centre of the universe, and that remains its location for the Israelis and the Palestinians.

Medieval cartographers used to draw the holy city of Jerusalem at the centre of the universe, and that remains its location for the Israelis and the Palestinians.

As the Camp David negotiators laboured away through the nights, no issue was tougher, more politically explosive or more burdened by differing versions of history and faith.

It has been the largest stumbling block in the talks, the biggest reason for the all-nighters, the tantrums and the threats by both sides to leave the Maryland mountains to return to the Middle East.

Yet the mere fact that formulas for its future were discussed is significant. Some see it as a breakthrough in its own right. "There are no taboos any more, and that is an unbelievable change," said Avraham Burg, speaker of Israel's Knesset, and a leading light in the PR team pushing Israel's case during Camp David.

The Jerusalem question places a vast weight on the shoulders of both Yasser Arafat and Ehud Barak. The city is the third holiest in Islam, and the entire Muslim world expects Mr Arafat to defend their interests.

So do his own people, who have clung doggedly to their dream of a capital in east Jerusalem, despite the harsh realities faced over the years by the 200,000 Palestinians who live in the city's eastern half - the demolition of their homes by Israeli bulldozers and the throttling growth outside Jerusalem's eastern perimeter of large, permanent Jewish "settlements".

Yasser Arafat has said that Jerusalem is the one issue he fears could lead to his assassination if he gets it wrong.

And, according to the Arab newspaper Ashark al-Awsat, he has told Mr Clinton and Mr Barak that "the Arab leader who will give up Jerusalem has not yet been born".

Mr Barak's position is not easy either. Anything perceived to be a departure from his much advertised unnegotiable "red line" on Jerusalem - his promise that it will be Israel's "eternal and undivided capital" - will unleash a political storm that could sweep away his already crippled government.

The ultra-Orthodox community would lead the charge, doubtless egged on by Ehud Olmert, the right-wing mayor of Jewish Jerusalem. But the city's status as Judaism's spiritual heart has percolated through to secular Jews, many of whom struggle to accept the idea of a shared city, two capitals side-by-side.

The fact that in parts of the city the Palestinians already have "de facto" control at a civilian municipal level tends to be forgotten. That may be because Jewish Jerusalemites can be wildly ignorant of their Arab neighbours as they rarely cross the Green Line (the border before the 1967 war) into Palestinian areas.

Palestinians, however, regularly trudge across the unmarked boundary from their own usually shabby streets in search of work among the restaurants, boutiques and leafy avenues of the far better funded, far better resourced, cosmopolitan Jewish western half.

It is within these incredibly tight political parameters that Messrs Arafat and Barak have sought to work over the past eight days, fighting off the temptation to postpone the Jerusalem question again on the grounds that it is still insoluble.

According to Israel's Maariv newspaper, the Israeli delegation tried to crack the Jerusalem riddle by some deft semantic engineering. They pushed a carefully phrased deal in which the Palestinians would get " implied sovereignty" over Palestinian neighbourhoods in east Jerusalem, Muslim and Christian quarters of the Old City and safe passage to Islam's holy sites on the Temple Mount.

In return, Israel would be allowed to annex a bloc of heavyweight "settlements" - urban towns, in reality - including Pisgat Zeev and Maale Adumim, which were strategically built by Israel outside the city's eastern edge on the occupied West Bank in order to secure control over Greater Jerusalem. But, mindful that Israel would remain in overall charge, Mr Arafat turned the plan down. Several other proposals have also emerged, including one in which Pisgat Zeev and Maale Adumim would be the Israeli-controlled northern and eastern gates of the city, while the Palestinians have de facto autonomy in their neighbourhoods within.

Israel has, of course, tried to be creative before, by agreeing to give the Palestinians full control of three Arab villages on the edge of east Jerusalem, including Abu Dis, in the hope that they will accept these as the site of the capital. But, although the Palestinian Authority has constructed a parliament in Abu Dis, its officials regard the transfer - which has been agreed by Israel, but not implemented - as a grossly inadequate answer to their desires for sovereignty and for an Israeli withdrawal to the borders that existed before the 1967 war. It has not escaped their notice that Abu Dis is dominated to the east by Maaleh Adumim, or that there are moves afoot among the Jewish settler movement to build a Jewish suburb right on the border of Abu Dis, only yards from the parliament.

But all solutions will be hard to turn from theory into practice. Blood has been spilt all too often as Israelis and Arabs, Muslims and Jews grapple for control. The bloodbath of October 1990, when 18 Arabs died on the Temple Mount after the Israeli police opened fire, is testimony to this. As one Israeli minister observed, Jerusalem's Old City is the most sensitive place on the planet.

It was ever thus. That much was clear even at Israel's hour of triumph in 1967, when its army had swept through the city. When someone tried to celebrate the victory by hoisting the Star of David over the Dome of the Rock, the Defence Minister, Moshe Dayan, immediately ordered it to be lowered. He knew what could happen - and what still can.