The Irish seem to have been at war, off and on, forever, or at least for the last few centuries. Certainly, in the last few years, there have been periodic terrorist or guerilla-style attacks between the those in the northern part of the island, and those in the southern part.
The newspaper and TV routinely report these conflicts as the struggle between the Protestant and Catholic parts of Ireland. To be sure, southern Ireland is largely Roman Catholic, and northern Ireland is mainly Anglican. But is that really what the conflict is about?
Remember, Christianity in Ireland split into the two group in 1532, when Henry VIII started the English Reformation.
But the warfare in Ireland has been going on since the 1100's, and perhaps even earlier, when there was no religious division on island.
The fighting is Ireland is about the same things that most other wars are about: land, power, and money. It is not a religious war.