Well, England did invade and take over their quiet lifestyle? Just like they did the American Indians? So does that justify the American Indians being "ALLOWED" to live amongst their terrorists?
Plus, the Irish were tortured by the English(terrorists? is a new term to apply to what they were back then), they weren't allowed to do anything that reminded them of who they were. Their very dignity was stolen from them, like skinning a cat!
Sorry, but England did not "invade" Ireland in the "12th century." High King Rory O'Connor expelled Dermot MacMurrough from the throne of Leinster, and Dermot then went to England (just a hundred years after the Normans had invaded England from France to which they had come from Scandinavia) to seek Normans to fight for him and help him get his throne back (which he did). He rewarded one of the Norman knights with a marriage to his daughter, then died, which made this Norman knight King. Henry II, hearing this, came over and insisted that Strongbow (the Norman Knight) acknowledge him as overlord with the title of "Lord of Ireland." Modern nationalism did not exist in the Middle Ages (everyone was an overlord to someone else) and it is at best ignorant and at worst malicious to interpret those events in light of modern nationalist concepts.
As to the Irish fight against England being equivalent to America's, America was an English/British colony that fought against the mother country for ideological/philosophical reasons. No American claims to have some sort of mystical tie to the land of America. Irish anti-English nationalism predates modern political philosophy (it was simply rule by an Irish king vs. rule by an English king). It is based on mystical nationalism, the idea that the people we know as Irish are "indigenous" or "autochthonous" or have some special mystic connection to that island which magically entitles them to being ruled only by other people on that island and which renders any other situation some sort of self-evident blasphemy of the Sacred Soil. Sorry, but not having sprung from the soil of anyplace, I have no patience with others who claim that mythical origin. Only one man in all of history "spring out of the soil"--'Adam HaRi'shon, who sprung from the soil of Har HaBayit and then removed from there and brought to Gan `Eiden, which is somewhere near Chevron. Perhaps it is their knowledge of our common origin and decidedly non-autochthonous natures that the Jews are so hated by the world's "nationalists."