It seems inevitable that Ireland will become united, both because of demographic trends - a nationalist majority in 50 years - and because of the persistence of republicanism (500 years). Also, British public opinion is for withdrawal. If this conflict continues as it has, then nationalists will only vote for unification if their standard of living can be maintained. Maybe Unionists should negotiate now while they are in a position of relative strength and therefore maintain peace after unification, as loyalists no doubt will adopt the IRA's current position.
Unification, if negotiated now by the Unionists, could bring the stability for economic growth and prosperity for everyone.