The way to do that is to repeatedly show the footage of 9/11 to Americans. The media won't do that, and they probably started backing off of it by 9/18 because they didn't want to "inflame" Americans. Then, they began downplaying the coverage of other Al Qaeda attacks like the Bali bombing in order to minimize Bush's war on terrorism.
I think it takes an annual commemoration to get the media to replay the footage at all, even if only annually.
-PJ