The existence of modern conspiracies should hardly be surprising. And are precisely the business of intelligence services such as those with established links to the attackers. The attack itself was, by definition, a conspiracy. There's a great deal of conjecture about who exactly was involved in that conspiracy besides the attackers themselves, and a great deal of evidence both concrete and circumstantial. Too much for a single HN comment. But I've made no claims about that beyond "Rebuilding America's Defenses" being conspicuously prescient. Which it demonstrably was.
