I have a slightly different take. A terrorists purpose is in fact to create terror. AQ, however, is not a terrorist group, but rather an Islamic army, whose goal is not to terrorize, but to kill every infidel and establish a worldwide Islamic state. Making threats and trash talking is not AQ's style, which is one of the reasons we should stop wasting time with EOM, the imposter. When AQ is ready to strike it will, and the advance warnings, if any, will only become apparent after the fact.