No similarity at all. Suppose that it true (and I am not saying it is) that Irish Catholics are sympathetic to terrorists in their midst. Is this because they are Irish or because they are Catholic? Clearly the first: no other Catholics, anywhere in the world, are or were blowing up buses. The Pope never proclaimed, as do Imams EVERYWHERE in the world, that blowing up babies is justified when it occurs on "occupied" territories.
In contrast, American imams urge us to "understand" the Sep 11 attackers, and poor "Palestinian" people that are "humiliated" daily by the Israelis (the Joooss). You have a religion that justifies killing if you feel humiliated --- and, yes, that is not just the current feeling among Muslims; it endured over 1400 years.
So, even if it were true that all Irish Catholics were sympathetic with terrorists in their midst, it would be explained by the fact that they are Irish, not that they are Catholic. Of the 31 armed disputed around the world 28 involve Muslims: against America and England, against Buddhists in Thailand -- -you name it. That's the difference.
Islamofascists are terrorists.
Muslims who do not denounce Islamofascists are not terrorists. They may be cowards or they may be sympathetic, we cannot read their minds and souls, but I would say that Islam is a religion, not a terrorist organization. When the Soviet Union made communism a state religion it did not make everyone who lived behind the Iron Curtain our enemy. PS: I agree with Ann Coulter's remark made in Sept 2001 - One way to end the terrorism is to convert them all to Christianity. THAT would be the ideal solution!