The chief Israeli negotiator at the Wye Plantation in Maryland last October was Benjamin Netanyahu, then prime minister of Israel, who probably did not intend to implement what he agreed. No sooner had he got back to Israel than he froze the accords, claiming Palestinian non-compliance.
When Ehud Barak defeated Mr Netanyahu in the Israeli election earlier this year, he promised to implement Wye, but wanted to renegotiate.
Yasser Arafat, the Palestinian leader, said at first he did not want to change a signed agreement, though the Wye accord is itself a renegotiation of two earlier agreements reached in 1995 and 1997.
At the centre of the Wye agreement is a further Israeli withdrawal from the West Bank. This would give Mr Arafat 13 per cent more of its territory under his partial control and 14 per cent under his total control. The whole redeployment would take place in three phases over 12 weeks.
Mr Barak wanted to delay the final phase and fold it into the so-called "final-status" agreement, arguing that withdrawal now would cut off some Jewish settlements.
The most difficult issueswere deliberately postponed, under the 1993 Oslo accords, until final status talks. When they start, the two sides will discuss the future of Jerusalem, Jewish settlements in the occupied territories, Palestinian refugees, borders and the status of the new Palestinian quasi-state. But Mr Barak said on the night he was elected that he would not compromise on Jerusalem and 3.8 million Palestinian refugees should stay where they are. Mr Arafat suspects that the final status talks will fail, so he wants everything he can get now.
Mr Arafat also needs to show his own people that the seemingly endless negotiations of the last few years are producing dividends. This is above all true of prisoners. At the end of last year there were 2,277 Palestinian prisoners in Israeli jails according to the Mandela Institute. Of these 580 are serving lengthy prison sentences.
At Wye last year, Mr Netanyahu promised to release 750 prisoners in three batches, but most of those freed were petty criminals. The Palestinians were infuriated. Mr Arafat was accused of letting his own men rot in prison.
The house of Abu Mazen, one of his chief negotiators, was stoned. Marches and hunger strikes by the relatives of the prisoners attracted mass support. It is not an issue on which the Palestinian leader can easily compromise. The Israeli government now says it is willing to release 350 prisoners, while the Palestinians want 400.
Ever since Mr Arafat arrived there in 1994, Gaza has been isolated. Its 1 million people cannot travel to the West Bank. This should now change. Two safe passage routes will be opened, one to Hebron in the south and the other terminating near Ramallah in the north. Even here, however, the extent of Israeli security measures is still unclear.