The Palestinians blamed the attacks on American policy toward Palestine. The doomsayers predicted economic collapse, the superstitious touted forged predictions of Nostradamus. The attacks on the US were the release of an alpha version of a new technology for destroying modern civilization. What was done by one archfiend can and will be done by other rogues. The origins of these attacks need not be related to the Middle East or even to politics.
Civilization has many enemies, with diverse motivations.
Fortunes can be made by proper speculation in stocks. Cults may be convinced they need to bring about the end of the world and the second coming. Blackmailers will find it convenient that they can paralyze a continent with a nominal investment. It will probably take several such attacks before there is a coordinated and serious effort to control the threat. There may not be a feasible solution, but we will not even begin to find out until we define the problem properly, rid ourselves of preconceptions and separate the trickle of possible facts from the flood of dysinformation and false leads.