Dublin — Newly elected Irish Prime Minister Charles J. Haughey will have two main aims when he talks with President Reagan during a St. Patrick's Day lunch in the White House March 17.
* He will try to reassure American investors in Ireland that talk of Ireland's economic malaise has been exaggerated in the bitter election battle between the political parties.
* And he will tell President Reagan about his policy toward ending the crisis in Northern Ireland.
It is clear Mr. Haughey has abandoned the approach of his predecessor, Dr. Garret FitzGerald, to encourage reconciliation between the Protestant and Roman Catholic communities in Northern Ireland.
Northern Ireland's politicians are reported to be ''amazed and furious'' about the belligerency of Mr. Haughey's attitude toward Ulster. Within two hours of his adoption as the new prime minister Mr. Haughey was talking about the withdrawal of the British military and political presence in Northern Ireland.
Britain's minister for Northern Ireland James Prior was taken aback by Mr. Haughey's comments and has asked to see him as a matter of urgency.
Mr. Haughey believes a deal can be worked out between the governments in Dublin and London for a new political arrangement to include Northern Ireland's politicians.
His emphasis, though, is to press on toward Irish unity in spite of the reaction from Protestants in Northern Ireland.
Mr. Haughey has scrapped Dr. FitzGerald's proposals to amend the Irish Republic's Constitution to delete references to governing Northern Ireland. The Haughey administration also will not consider Dr. FitzGerald's plans for social reform and the introduction of divorce courts.
Mr. Haughey will be in the United States only until tonight (March 17) because of the pressing problems he faces at home.
* A budget has to be put together by March 25 incorporating measures to cut back foreign borrowing, reduce inflation (23 percent), and prune government spending.
* A start has to be made on continuing talks by London and Dublin over the future of Northern Ireland, which Mr. Haughey says, is his first political priority. Urgent talks are needed with Ireland's partners in the European Community (EC) to halt proposals for agricultural price reform which threaten to bankrupt Irish farmers.
Mr. Haughey's dependence on support from extreme socialists and Irish Republicans in the new parliament is constricting his options. With a free hand he would encourage private industry to lead Ireland out of the recession.
But the handful of independents who are keeping him in office are demanding increased public expenditure to create jobs and improve social amenities, particularly in inner city Dublin.
Bankers and economists in Dublin are watching to see how Haughey manages to walk such a perilous tightrope. They believe the overriding message of the last general election was that people are prepared for stiff medicine and an end to costly promises.
But Haughey appears to have tied himself to some extremely expensive deals to secure his premiership. A young independent deputy in the Parliament has secured a five-page agreement from Haughey to revitalize Dublin at an estimated cost of 150 million Irish pounds ($223.5 million).