Well, it matters what he did, as we're now dealing with the results. Moreover, it's better to learn from the mistakes of the past so as not to repeat them.
Now, we have a few thousand truly evil people in the Middle East committing acts of savagery under the banner of ISIS. They are radicals who are not afraid to die for their cause, and who believe that their god will see to it that they succeed in their goal of world domination.
So, what do we do?
It is our problem to a degree, since we set the stage for the uprising and since we still rely on the region for oil. It seems to me that it is also the problem of a lot of other nations as well, including, of course, Egypt, the last one to have been attacked.
So, do we go in alone, guns blazing, to free the world from evil and set things right? Remember the learning from the past thing.