You realize of course that the Soviet invasion of Afg was during the Cold War, and was just the type of threat that the West was helping defend the Middle East from. Thus the tolerance for our presence. Then the Gulf War. Bin Laden offered to lead a similar effort to deal with Saddam, and was rejected and instead US forces brought into the Kingdom. This was a major decision for the King. He knew it violated everything his populace believed, but also knew that he had no other viable choice to preserve his kingdom. This was post Cold War. The tide had turned. We were no longer keeping the Soviets out, we were now for all effects the mercs of the King guarding his status as King and fighting other Muslims.

Then we decided to stay in the Kingdom. This created an issue for Bin Laden to focus on, and so he did. And for populaces of countries that had lived through generations of western governmental manipulation, it was a message that resonated.

Not all are fighters, only a few. But most essentially agree with the message and respect Bin Laden for daring to stand up. In between there is a wide range of positions and degrees of participation.

Oh, and a mediator has no position, he just facilitates a dialog between parties that have too many issues to be able to negotiate. Its a suitable role for the US to take.