Thanks for mentioning the IRA.
tsk tsk talking about self-centered nations. Nah, that trend stared in the second part of the 19th century with revolutionary leftie organization/cells that on a small scale keeping alive traditions of the French Revolution's terror.
In modern times the WWII seems terror attacks, sabotage and diversion used across the continents as yet another tool of the total war. After the war Jewish settlers in Palestine used terror bombs (not only but the bombs were most effective) attacks against British soldiers as a way of reaching their own political objective.
Used now and then bombs attacks against civilian population were in fact popularized by the IRA, themselves being influenced by the Maoist ideology and terrorist cells in the Latino America.
Next Palestinians took up the mantle of perfected that adding suicidal boomers caring vests packed with explosives in one. That was out of necessity really because Israeli security didn't give them much leeway - classical plot of planting a bomb more oft flailed than not and those who were planting a bomb were more oft than not killed anyway.
From Palestinians the Muslim world took over as added their own religious based ideology they fitted the narrative of Islam well.
In Ireland, Muslims are not alienated
Sure because they Muslim are few and between in Ireland.