The Irish language has long been regarded in the popular mind as a correlate of Irish nationalism. A model expounded by the sociolinguist, Joshua Fishman, is applied to the evolution of Irish as a nationalist icon, and it is demonstrated that its divisive potential developed only gradually. In fact, it was an object of affection and admiration for many influential 19th century Protestants and unionists. In the 20th century, the language became increasingly polarised for political ends, and after Partition was largely rejected in the education system as experienced by unionist children in Northern Ireland. It is argued that such an overwhelmingly anglocentric orientation, not just in language, but also in history and geography, has paradoxically served to exacerbate the Troubles. It has alienated unionists from cultural capital which rightfully and historically belongs to both traditions, and in so doing has promoted a "frontier mentality" among them. Somewhat in a spirit of definition by opposition, they are currently turning to Ulster-Scots; yet by adopting a more positive attitude towards Irish, unionists would simultaneously reconnect with their historical roots, and might deprive the language of its potential as a political weapon to be used against them. (Contains 8 notes.)