I was not suggesting that it was the IRA, however the pyschological message of the attacks seems to be "don't use public transport you are not safe" in large cities like london this could cause the city to grind to a halt which I believe is the primary objective of the attack ie to ruin the economy. Re Al queda yes they are the most likely suspect. If it was suicide bombers I would not want to be Arab/muslim and be in that city. In some ways the fear of suicide bombers would be more powerfull than a one off attack like 911 or a biological attack.
