The United States invaded Afghanistan on October 7, 2001.
The only real evidence that I have seen that the U.S. had around the time to connect Osama bin Laden to 9/11 was that grainy videotape the Pentagon released on Dec. 13, 2001 that allegedly shows OBL taking credit for 9/11. However, besides the allegations that this video may be a fake, the video was said to have been made in "early November" of 2001, one month after the invasion.
So my question is...
What evidence did the United States have on Osama bin Laden and other members of Al Qaeda for being responsible for 9/11 to justify their invasion of Afghanistan to go after them?
Please post your answers in the comments section.