Sjakie said:
You ask an interesting question there: As far as i know, the only ones that commit suicide attacks while unprovoked (meaning: not in a state of war) are religiously motivated individuals that are exploited by their powerbase. Any other group or country would at least give more indication that they would strike at their enemy. Not to mention they would not kill themselves in the proces that willingly. You might say the japanese (kamikaze) in WWII defy this, but they where at war and the Japanese Emperor was worshipped like a divine figure at the time. Not to mention they struck a military target, not a civilian one.
Religion is not the scapegoat, it is the cause! To be more precise it is the selfproclaimed powerbase of a religion that has others do its dirty work for them. All major religions suffer from this problem as long as they exist. No country would even begin to attack civillians from another country on that scale for something as simple as a revenge-attack, they would be reasonable enough to go for military targets first before the hell of total warfare would break loose.
So the anser is: No, such an attack would not occur without the religous aspects that this attack had.
There are instances where State-ideologies get raised up to a point where people will kill themselves for it, but those are just as bad as the blind devotion that religion requiers and are thus not that different from religion.
They may be just as bad, but they aren't religion, thus telling that yes, such things could happen without religion.
The first problem I think I see is that you see those attacks as if they were almost performed by a country, when they were not. They were religious people no doubt, but the fact that they held allegiance to a continent without actually representing it meant they could perform such attacks without declaration of war (though they did eventually, but it was more of a rally than a declaration of war).
You know who's done something like that without it being in the name of religion? The IRA, more specifically the RIRA. Sure, the IRA have performed atrocities in the name of religion, but they have done far more in the name of their country, and have killed countless innocent civilians without provocation, because they want England out of their country and a unified Ireland. One of those arocities was the 1998 Omagh bombing and the other an attack on a barracks in Northern Ireland that is supposed to be there through treaty, and soldiers and civilians were killed and injured because the RIRA didn't want them there, and yes, they also indulged in suicide bombings.
The parallels between the two are that both England and America had their hands in both countries in a negative way, but the difference is that the ones behind September 11 are calling for the destruction of America in the name of god, while the IRA and RIRA are not.
As for the Kamikaze, it's easy enough to cast off such things as them being so devoted to their emperor, but not only was such a thing done by individuals during WW2 before it was adopted by the military as a last ditch effort, but suicide has long been a large part of Japanese society, to abstain from shame. Extend it to the Kamikaze and they are trying to prevent shame from falling to their homeland, and none of this was religiously fueled.
The black Tigers of Sri Lanka have also suicide bombed civilians and others, but I won't go into that.
Nationalism and Idealism are just two more reasons why you would kill people, civilian or otherwise, at the expense of your own life.