Dublin — A ''new Ireland'' may soon be in the blueprint stage. The Irish government has decided to set up a new political forum to try to design a revised framework for this currently divided island. And today, St. Patrick's Day, Irish Foreign Minister Peter Barry was scheduled to present the proposal to President Reagan and other American leaders in Washington.
The forum will bring together Ireland's moderate nationalist parties both in the independent republic here in the south and in British-ruled Northern Ireland. These parties favor peaceful reunification of south and north. Parties that support violence - like Sinn Fein, the political arm of the Provisional wing of the illegal Irish Republican Army (IRA) - will be excluded.
Representatives of Northern Ireland's 1 million Protestants (mostly Unionists who favor continued union with Britain) are considered certain to refuse to participate. This means, in effect, that the north will be represented by the Social Democratic and Labour Party. The SDLP is the main political voice of the north's half-million Roman Catholics but in recent times has been increasingly challenged by Sinn Fein for electoral support.
The chief task facing the forum will be to devise ways to guarantee Protestant rights and traditions in the hope that they may eventually agree to sever the British link and join with the overwhelmingly Catholic republic (population 3.5 million) in a united or federal Ireland.
American moral support for the idea would help, too. Foreign Minister Barry was scheduled meet President Reagan both at a St. Patrick's Day lunch hosted by House Speaker Thomas P. O'Neill Jr. and at a reception in the Irish Embassy. Mr. Barry was also due to have talks with Secretary of State George Shultz and National Security Adviser William Clark.
The Irish government here in Dublin has long been concerned about Irish-American support, in money and arms, for the Provisional IRA. These anxieties came to a head when Michael Flannery, a self-confessed gunrunner and IRA supporter, was chosen to be chief marshal of the New York St. Patrick's Day parade.
So infuriated was the Irish government by this choice that it banned participation by such bodies as the Irish Tourist Board and Aer Lingus, the national airline, in spite of the consequent loss of publicity and therefore probable loss of revenue.
Dublin sees the discussions in Washington about the ''new Ireland'' forum as an important counterbalance to the parade's possibly pro-IRA leanings. President Reagan, following the example of such Irish-American congressional leaders as Speaker O'Neill and Sen. Edward Kennedy (D) of Massachusetts, has in the past strongly condemned terrorism in Northern Ireland. He has also urged Irish-Americans not to contribute to IRA ''front'' organizations like Noraid, the American charitable organization led by Mr. Flannery which in 1981 was ruled to be an agent of the IRA.
In the early 1970s, the amount of money contributed in the US to such organizations was estimated at between $1 million and $2 million annually. After years of counterpropaganda by Irish and US leaders, this fell by 1980 to an estimated $200,000. But it increased tenfold during and after the hunger strike in 1981 in the Maze Prison near Belfast which brought about the deaths of 10 prisoners, members of the Provisional IRA and another terrorist group, the Irish National Liberation Army.
The Irish government now hopes to persuade Irish-Americans that this support is a major obstacle to a peaceful settlement of the ''Irish question'' and to the achievement of equal rights for Catholics in Northern Ireland. It wants them to understand that the IRA aims to seize power in both parts of Ireland and to ''destabilize'' the democratic institutions of the Irish Republic.