The document is in essence a reassertion of marriage vows. When the two Yemens - north and south - sealed the knot four years ago, the move was widely welcomed in the Arab world. For in a region littered with past treaties of union, carried along by puffs of empty rhetoric about Arab unity, here were words translated into action. Only the Saudis, always dismissive of their southern neighbour, were less than enthusiastic about the creation of a larger, single state on their borders, especially one which had not supported the Saudi-led Arab coalition against Saddam Hussein of Iraq.
King Hussein is an eager host to this planned meeting. Always one who sees himself as a mediator in inter-Arab disputes, the Hashemite monarch also shares with the Vice- President of Yemen, Ali Salem al- Baidh, the claim to be descended from the Prophet Mohamed. Yemen and Jordan adopted similar stances during the Gulf crisis, for which King Hussein is still vilified by the Saudis and the Kuwaitis.
Yemen's act of union was not its only unusual act. Last year the country successfully held parliamentary elections that were among the freest held in the Arab world. But the divisions between north and south, between different power structures, have never been properly overcome. The differences are part ideological, part cultural, part tribal. It was never going to be easy to marry the traditionalist northern part of the country with the south which, after the British withdrawal from Aden and the protectorate around it in 1967, became the nearest thing to a Stalinist state in the Arab world.
The differences finally erupted in July, plunging the country into a political crisis. Mr Baidh skulked off to his headquarters and power base in Aden, demanding political and economic reforms, while President Ali Abdullah Saleh in effect ruled from Sanaa in the north through his General People's Congress.
In the lead up to the planned meeting in Amman, accusations have been traded between the two camps. Mr Baidh's Yemen Socialist Party has said that forces loyal to President Saleh's men had been plotting to shoot down Mr Baidh's plane on its way to Amman. A new row has erupted over the appointment of a government of Abyan province in southern Yemen.
On Wednesday, President Saleh's party accused the southerners of preparing for a 'bloody confrontation' by cutting water and power supplies to a police camp in Aden. Both sides accused the other of sending troops to the former border between north and south.
Each side is being asked to make concessions. President Saleh is being asked to loosen his control over the security services and the treasury. Mr Baidh is required to renounce his control over the rich oil fields in the south, which enable him to run the south as his personal fiefdom. A further complication is that the third party in the coalition government, the Islamist Islah party, has refused to support the reconciliation meeting.
The North-South union is an uneasy match, yet both sides remain committed at this stage to maintaining the union, even if they find it difficult to live together.