I usually wouldn't get involved in any of this business. I am not arguing that plenty of terrorist groups are not muslim but the IRA is not a terrorist group...even if they were a terrorist group they are nothing like the muslims.
I agree. But they are classified by someone, somewhere as terrorist. It's all relative. If you're Irish, the IRA might be freedom fighters. If you're British, they may be terrorists.
This notion of absolute good and evil is the result of heavy propagandizing, which is the speciality of every government throughout history. The only way to get people to go along with perpetual war, high taxes, massive public debt etc., is to appeal to their petty bigotries and cultivate fear and paranoia in an atmosphere of conditioned ignorance.
The Soviets did it, the Nazis did it, the Islamic fundamentalists do it, Christian and Jewish fundamentalists do it, and yes, western democracies do it as well.
For the record, I sympathize with the IRA. They are secessionists. I believe everyone has a fundamental natural right to secede. Preferably peaceful secession.
EDIT, meant to add, there is no "the muslims". Suicide terrorism is basically done for the same reasons the IRA bombed. The CPOST link above, and the work of the Director of CPOST, Dr. Robert Pape (Dying to Win) covers this phenomenon. Terrorism is not religiously motivated, it is motivated by conditions of political alienation and occupation.