My suggestion is a lot less offensive than the fighting that killed 3,600 and wounded 30,000 people.
Even their own countrymen/women in Ireland didn't support them.
Barrister and media personality Joe Brolly recently set social media alight with some comments taken from a longer interview. Brolly asserted that the Northern Ireland Troubles saw the emergence of a southern orthodoxy whereby "nationalists in the north were to blame".
He was then joined by one-time MP and long-time rights activist Bernadette McAliskey, who argued that "the northern Catholic was and still is looked on by the southern state as not worth the trouble". The words aroused a strong sense of approval among a considerable demographic within the north; many of whom feel that southern Irish society did indeed 'fail' them.
Nonetheless, it is clear that a considerable majority of southerners were critical of the PIRA and wider republican violence and it is this, rather than blanket rejection, which forms the feeling of historical alienation among a certain northern cohort. As with most northern Catholics, the southern Irish could see the logic of the civil rights movement as a response to the situation faced by the minority there. But they could not see the proportion or moral justification in endlessly bombing and shooting British soldiers, and more especially policemen, civil servants, and members of the public.
Going even further back in history an often forgotten fact about the Battle of the Boyne in 1690 was that the Pope of the day supported the Protestant King William of Orange against the supporters of the deposed Catholic King James II of England.
This unusual alliance came about because the Papacy, then a world power, was at odds with King Louis XIV of France, who was an ally of King James.
It is said that a Mass of deliverance was celebrated in Rome after King William's victory.