Seymour Hersh provides a very plausible deconstruction of how chemical weapons were used in an attempt to draw the United States into military engagement with Syria last year---by the Turkish government in cahoots with anti-Assad Syrian rebels. Hopefully you have heard about the leaked YouTube audiotape in which planning for a Syria false flag attack is discussed. It did not get much mainstream press, though both Voice of America and RT carried the story.
Hersh pays close attention to what we knew and when did we know it--and what did the administration do about it. An important read.