:I'm okay with splitting the article, but I do not think US/Israel is where it most obviously breaks. It might be more natural to have three: maybe Economic, Political, and Social 9/11 Conspiracy Theories; Or maybe 'They let it happen' and 'They made it happen.' 

 :We should not choose a title that mis-describes (unintentionally) the nature of the material. I think subsuming Jewish under Israeli glosses over the elements of anti-semitism that are present in some of (by no means all of) the better-known conspiracy theories, and takes them out of their historical context. 

 :This is not the place to decide whether conspiracy theory is appropriate for article titles. I think a proposal for that is on the table at Wikipedia:Title Neutrality. Tom Harrison