Why "Islamist threat" not Al-Qaida versus the IRA?

I want to apologise for starting yesterdays post with same article as today but then I became embroiled by the whole religious theme from yesterdays Guardian. Today I will examine the topic in the title.

The opinion of Metropolitan police commissioner, Sir Ian Blair, is not the question here, rather what I am wondering about is why was the comparison made between islamic terrorism to the IRA rather than either Al-Qaida to the IRA or islamic compared to catholic terrorism?

As a Dubliner who grew up in London, I was both too young and have no opinion, one way or another, as to whether Northern Ireland should (have been or ) be unified with Eire or not. What is clear is that this dispute was between at least some Northern Irish catholics, as represented by the IRA and its ilk, who did want unification and some Northern Irish protestants, as represented by the UDF and similar, who did not. There was and is undeniably a religious component in this dispute but it is local and has specific goals, theoretically achievable as well. The methods to achieve these goals were heinous and horrendous but it seems impossible to abstract or generalise to an idea of catholic terrorism from this.

Whilst the actual Guardian headline emphasized islamic terrorism it is not clear whether Ian Blair was talking specifically about al-Qaida or not. As quoted in the article

"The IRA, with very few exceptions, did not want to carry out mass atrocities, they didn't want to die, they gave warnings and they were heavily penetrated by the intelligence services. None of those apply with al-Qaida and its affiliates."

I am sure most would agree this makes al-Qaida a worse and more upredictable and dangerous terrorist organisation (if that is the right term to apply to them) than the IRA. I am not sure if this is a quote or a paraphrase but the article leads with:

Britain faces a threat of "unparalleled nature" from Islamist terrorism which is greater than the dangers ever posed by the IRA, the Metropolitan police commissioner, Sir Ian Blair, said yesterday.

By comparison to the idea of "catholic terrorism", in the case of Islam it seems to be that both Sunni and Shia - very loosely analogous, for our purposes here, to protestant and catholics - are involved in terrorism - this alone defeats my initial question of why not "catholic terrorism", the real comparison should have been posed as "christian terrorism"! Further one cannot locate this to specific countries or even continents, since apart from it is not just being arabs, when anyway Iranians do not consider themselves arabs, we have had terrorist attacks from african Somalis in our own London! It seems that the only common denominator is Islam, as these extremists themselves usually declare.

So all in all you might consider my original query rather pointless. I made it in the interests of the theme of this blog, that is was there any double standard going on in how these issues were being represented and, in this case, the answer is clearly not. This does make me wonder whether there has been anything equivalent to this current type of threat in the history of mankind. It appears me that all the old and new, national and international, religious conflicts from the crusades to Northern Ireland are very different to this current threat.