I saw Fahrenheit 9/11 a week ago, but never got around to commenting here. As markv says, it's hard to do the film justice, so please see it if you haven't. Here's my take:
Fahrenheit 9/11 is propaganda. It doesn't try to be fair, and it doesn't pull any punches. It's also not easy to watch. Watching it, though, you do get the feeling that something big and new is going on. It's not the war itself, or the politics surrounding it--we've sort of become inured to those. It's not even the Bush Administration Conspiracy Theory on which the film is based. Whether or not you buy into it, we've all heard tell of sinister motives in high places. The big and new thing is, instead, an escalation of the dialogue surrounding the war.
The sentiments in Fahrenheit 9/11 are familiar--a lot of us have been opposed to the war from the start. The "revelations" in the film are also not new, at least to anybody who reads more than the front page. But the beauty and the horror of the presentation, and (it turns out) the scope of the audience it's reaching, are stunning. Considering the impact this film could have in this election year, I would be surprised if similar, opposing films didn't appear--and soon. For better or worse, the gloves have come off.
It remains to be seen if anybody can muster a suitable response. Moore is an incredible filmmaker. If Bowling for Columbine didn't show that, then this film certainly does. In it, Moore paints a picture of a crooked, manipulative, violent administration. He paints it almost entirely with the words and images of others, but especially with those of the administration itself. The funny, the ghastly, and the infuriating alternate and then blur together. He paints a vivid picture.
There are parts of Moore's painting that I believe, and parts that I don't. But the administration has its own painting, which it has fed to us in pieces for several years. Of all the stories I've heard, the official one is the least believable. If this film accomplishes anything, I hope it reminds people that there are other, often more plausible interpretations than the ones we're given.