I can understand sympathizing with irish republicanism. People often forget that most of the UK are not a member by choice per se. Ireland has technically been an occupied nation for hundreds of years, yet, they have never become fully integrated Brits. Their cultural identity has never really waned as is typical of nations that are occupied for long lengths of time by a people that share some cultural affinities. So I can totally understand why half the country is not enough for Irish repubs.

That said, The IRA "died" when the South was founded and was amalgamated as the official republic army. PIRA was the only real successor to the cause and they put down their guns back in '05.

Remaining remnants of the republican movement(such as RIRA) militant arm are mostly low brow thugs who are looking to earn a buck rather than unification with the south.

HOWEVER, honestly, the IRA (every incarnation), has often employed some shamefully cowardly tactics and have littered history with the corpses of hundreds of civilians. there is also a whole other side to republicanism in North Ireland, it's really such a difficult situation, I don't think there will ever be a compromise that will satisfy the republicans, short of England completely removing any and all presence there, which isn't a feasible expectation for several reasons.

Another important thing to understand about the IRA's conflict with the British government is that there actually is SOME altruistic logic behind their staying and occupying North Ireland. Hundreds of years ago when the british first invaded and annexed Ireland to make way for British colonists, nobody could have guessed eventually Henvry VII(I?) would come a long and reform the religious institutions from the ground up, vis-a-vis bodily ejecting the papacy and Catholicism and creating Protestantism. Now, for a nation that has historically been extremely vested in the Catholic religion, this came as something of a blow to Ireland.

let me elaborate, it easy to overlook King Henry's reformations as something that influences the more modern conflict between the IRA and the UK, but it has to be a major part of the sectarian violence that occurs in ireland today. The colonists that settled Ireland were mainly english protestants, so, hundreds of years later we develop a unique situation wherein half the people of the Northern districts are the ancestors of people that technically have no right to settle where they did, yet, have been there for generations and are as much Irish as any catholic.

One of the big reasons the Uk chose to stay in N. Ireland is because of those people, the loyalists/protestants who come from an ethnically English background but have been in Ireland since the time of their grandparents grandparents grandparents. At the time of the original Easter Rising in 1916 we are emerging from a period where many Catholics felt religiously suppressed, to make matters worse, Catholics were also socially repressed by the minority of protestants. Nepotism among protestant transplantees was rampant, to the point where it didn't matter how much money you had as a Catholic, you were forced to live in run down ghettos, your Republican, catholic government candidates had no chance of achieving real political status as the Protestants, whom (again), despite their minority status, rule a majority of the seats in the House of Commons.

So, I suppose these descendants of English settlers are not seen as truly Irish (by the repubs) despite their having been there for generations. I mean honestly I can understand both sides of this conflict. it really just goes to show how nothing in this world is black and white.

SO ALL THAT SAID, I don't see how an IRA presence in America would be at all good for anyone. HOWEVER, there WAS IRA presence in Boston for many years. Usually there to garner support from (then) recent Irish immigrants (whom no doubt became migrant because of the suppression of Catholics)in form of money, weapons, etc..

Now there would really be no reason for them to be in America. What would they get out of it? Anyone claiming to be "irish" is probably several generations removed from the Irish ancestor that originally settled in the US.