The label of Catholic terror was rarely used about the IRA :: Guardian

Karen Armstrong writes:

Almost every fundamentalist movement in Sunni Islam has been strongly influenced by Qutb, so there is a good case for calling the violence that some of his followers commit "Qutbian terrorism." Qutb urged his followers to withdraw from the moral and spiritual barbarism of modern society and fight it to the death.
. . .
We need a phrase that is more exact than "Islamic terror". These acts may be committed by people who call themselves Muslims, but they violate essential Islamic principles. The Qur'an prohibits aggressive warfare, permits war only in self-defence and insists that the true Islamic values are peace, reconciliation and forgiveness. It also states firmly that there must be no coercion in religious matters, and for centuries Islam had a much better record of religious tolerance than Christianity.

Like the Bible, the Qur'an has its share of aggressive texts, but like all the great religions, its main thrust is towards kindliness and compassion. Islamic law outlaws war against any country in which Muslims are allowed to practice their religion freely, and forbids the use of fire, the destruction of buildings and the killing of innocent civilians in a military campaign. So although Muslims, like Christians or Jews, have all too often failed to live up to their ideals, it is not because of the religion per se.

We rarely, if ever, called the IRA bombings "Catholic" terrorism because we knew enough to realise that this was not essentially a religious campaign. Indeed, like the Irish republican movement, many fundamentalist movements worldwide are simply new forms of nationalism in a highly unorthodox religious guise. This is obviously the case with Zionist fundamentalism in Israel and the fervently patriotic Christian right in the US.

In the Muslim world, too, where the European nationalist ideology has always seemed an alien import, fundamentalisms are often more about a search for social identity and national self-definition than religion. They represent a widespread desire to return to the roots of the culture, before it was invaded and weakened by the colonial powers.

I can't join in her opinion that fundamentalism is about nationalism or the seeming implication that nationalism is at essence a bad thing. I do concur otherwise in her opinion that Jewish, Muslim and Christian fundamentalists have a tremendous amount in common including the propensity of a minority to resort to violence. Note that, too, that fundamentalists are not necessarily the poor or the disposed, nor is the violent minority.