The agreement was reached between the British and Irish governments as well as eight northern Ireland political parties or groups. Three were representative of unionism: the Ulster Unionist Party, which had led unionism in Ulster since the early 20th century, and two small parties linked to loyalist paramilitaries, the Progressive Unionist Party (linked to the Ulster Volunteer Force (UVF) and the Ulster Democratic Party (the political wing of the Ulster Defence Association (UDA). Two of them have been widely described as nationalists: the Social Democratic and Labour Party and Sinn Féin, the Republican party affiliated with the Provisional Republican Army.   Apart from these rival traditions, there were two other assemblies, the Inter-Community Alliance Party and the Northern Ireland Women`s Coalition. There was also the Labour coalition. U.S. Senator George J. Mitchell was sent by U.S. President Bill Clinton to chair the talks between parties and groups.  A copy of the agreement was published in every house in Northern Ireland and the Republic of Ireland so that people could read before holding a referendum to vote. The main themes addressed by Sunningdale and dealt with in the Belfast Agreement are the principle of self-determination, the recognition of the two national identities, intergovernmental cooperation between the British and Ireland and legal procedures for compulsory power-sharing, such as inter-community voting and the D`Hondt system for appointing ministers to the executive.   Former IRA member and journalist Tommy McKearney says the main difference is the British government`s intention to negotiate a comprehensive agreement including the IRA and the most intransigent unionists.  With regard to the right to self-determination, two qualifications are recorded by the writer Austen Morgan.
First, the transfer of territory from one state to another must be done through an international agreement between the British and Irish governments. Second, the population of Northern Ireland can no longer be alone in united Ireland; They need not only the Irish government, but also the people of their neighbouring country, Ireland, to support unity. Mr Morgan also pointed out that, unlike the Irish Act 1949 and the Northern Ireland Constitution Act 1973, drawn up under Sunningdale, the 1998 agreement and the resulting British legislation explicitly provide for the possibility of a unified Ireland.  After the marathon negotiations, an agreement was finally reached on 10 April 1998. The Good Friday Agreement was a complex balancing act that reflects the three-strand approach. Within Northern Ireland, it has created a new de-elected assembly for Northern Ireland, calling for executive power to be shared by parties representing both communities. In addition, a new North-South Council of Ministers should be set up to institutionalise the link between the two parts of Ireland. The Irish Government has also committed to amending Articles 2 and 3 of the Constitution of the Republic, which appeal to Northern Ireland, to reflect the aspiration for Irish unity through purely democratic means, while accepting the diversity of identities and traditions in Ireland. Finally, a Council of The Islands should be created that recognises “all relations” within the British Isles, including representatives of both governments, and de-elected institutions in Scotland, Wales and Northern Ireland. Issues of sovereignty, civil and cultural rights, dismantling of arms, demilitarization, justice and police were at the heart of the agreement.