In the 17 years since Israel and the PLO officially recognised each other in the Oslo Accords, Middle East peace summits have come and gone, but the same obstacles stand in the way of a final agreement.
In the 1993 agreement, Article V spoke of ‘remaining issues’ – including Jerusalem, refugees, settlements and borders.
And still they remain.
Top of the list of stumbling blocks: Jewish settlements. The Palestinians want a freeze on new settlement building to be extended beyond the current 26 September deadline.
That is fiercely opposed by the settlers themselves and a significant part of Prime Minister Netanyahu’s cabinet.
The issue is central to the deadlock as it is so closely associated with other crucial issues, like what would a future Palestinian state look like, and where would its borders be.
The Palestinian Authority wants to establish its independent state based on the pre-1967 borders of the West Bank, the Gaza Strip and Jerusalem.
Ideally it wants Israel to withdraw completely.
But a compromise has already been struck, and certain settlements will be allowed to stay in exchange for territory elsewhere.
Israel has built a wall around its settlements, effectively annexing 40 percent of the West Bank, and has categorically refused to return to pre-1967 borders.
The second major bugbear is Jerusalem, in particular the east of the city, which has been at the heart of the dispute for decades.
In the Six Day War of 1967 Israel took East Jerusalem which had been under Jordanian control.
Since then, the Palestinians have continued to claim East Jerusalem as the capital of their future state.
But Israel has continued to build settlements there, considering it holy and indivisible.
They insist on keeping control of the ancient city which is home to some of the most sacred sites in Islam, Judaism and Christianity.
The Palestinians though have ruled it out.
East Jerusalem is home to 260,000 Palestinians and more than 200,000 Israelis.
Water plays a central role too. Israel draws 60 percent of its needs from the mountains of the West Bank and the Sea of Galilee. The Palestinians, who are banned from drilling wells and have to buy their water, are demanding their fair share.
And there are refugees. Four million Palestinians live in camps in neighbouring countries.
The Palestinian Authority is demanding the right for them to return. But Israel is worried about the prospect of being swallowed up.
These seem impossible issues to resolve – particularly when any concession is subject to the scrutiny of extremists from both sides.
Those in Gaza particularly, and Tel Aviv are watching to see that their representatives do not give ground to what they believe is the enemy.