As Prime Minister Garret FitzGerald of Ireland prepared for his visit to the U.S. this week, Americans sympathetic to the outlawed Irish Republican Army weren't cheering "Erin go bragh" (Ireland forever). The Irish Republic's taoiseach (leader, in Gaelic) for 15 months, FitzGerald damns the IRA as a "murderous gang" and rejects violence as an answer to Ireland's centuries-old strife.

FitzGerald arrives for his first official U.S. visit the week before St. Patrick's Day to celebrate Ireland's traditional ties to this country. After all, 43.8 million Americans, including the present tenant of 1600 Pennsylvania Avenue, share an ethnic touch of the auld sod. The 58-year-old law-trained intellectual will address a joint session of Congress and will lunch with the Reagans.

More importantly, FitzGerald will promote the New Ireland Forum, a commission set up last summer by four of Ireland's major nationalist parties to devise solutions to their political problems. Including representatives from both strife-torn Northern Ireland and the Republic, the conclave will announce its proposals this spring.

New York City's St. Patrick's Day parade won't be on FitzGerald's trip agenda. Last year the Irish government boycotted the celebration because the grand marshal was IRA fund raiser Michael Flannery. While FitzGerald doesn't have a quarrel with this year's grand marshal, union leader Teddy Gleason, he is annoyed by the selection of IRA fugitive Michael O'Rourke as honorary grand marshal. "We find it hard to accept that a convicted criminal should be honored in any way in the United States," he says. Instead, FitzGerald will fly to Brussels to spend the day with Belgium's Irish community.

The solution to Ireland's troubles proposed by the IRA and its American sympathizers—an immediate reunification of Northern Ireland with the Republic—would create an economic catastrophe for both, according to FitzGerald. Excluding the cost of maintaining soldiers in Ulster, Britain still spends $1.5 billion each year just keeping the economically ravaged province afloat. FitzGerald points out that his country's entire GNP is only $16 billion annually. "Bringing together the two parts of Ireland." FitzGerald notes, "would require substantial, continuing aid from Britain, from the EEC or from the United States, and possibly all three."

The Republic is also 95 percent Catholic, and its constitution reflects the church's influence: Divorce and abortion are banned. FitzGerald insists that major constitutional changes are necessary for reunification since Ulster is about 60 percent Protestant. "Most people in Ireland," he says, "accept that a united Ireland would have to give equal expression to the rights of Protestants and Catholics."

FitzGerald comes by his tolerance naturally. With a Protestant mother and a Catholic father, he is a practicing Catholic who credits his mother's Protestant relatives in Ulster with giving him his broadened perspective. The father of three, FitzGerald often draws on his wife of 37 years for political advice. "I am a critical sounding board," says Joan, 60, recently hospitalized with crippling osteoarthritis.

A modest man, the taoiseach has wide support. Says Dublin's leading Protestant minister, Victor Griffen, "He is a great hope. If the northern Protestants can trust anybody, they'll trust Garret FitzGerald.