I meant to say something about General Petraeus' comparison of the bombing situation in Iraq with that of Northern Ireland during the 1970's and 80's but Kieran Healy beat me to it.  All I would add is the reason for the vast difference in the number of civilians killed (British troops, RUC and loyalist paramilitiaries were always targets) by bombings in Northern Ireland versus Iraq was that the main purpose of the various IRA bombing campaigns was to wreak havoc upon the physical and economic infrastructure of Northern Ireland, and later England, in the hopes that continued British control would become not only unpopular in England but way too expensive for the British government and the Exchequer to maintain.  The car bomb was the principle weapon of the IRA but terror by mass casualty was not their aim, as seen in the fact that by and large the authorities received phone warnings well before the bombs went off which is something we haven't seen yet in Iraq .  This is not to minimize the impact of the violence in Northern Ireland but merely to point out that in some ways it seems we're talking about apples and oranges.