It's going to be difficult. They're in the midst of a civil war. They're busy shooting at each other right now. Knowing our government, we'll actually rationalize that killing the side that actually had nothing to do with the terrorist acts might help "maintain stability" in the region or other such nonsense.
In fact I know that this will be presented as an option by some CIA analyst (psychopath) and even discussed at length as possibly viable. After all, they could tell us anything and we'd believe them. Osama bind Laden is responsible for virtually every heinous crime around the globe.
We're probably going to hit a lot of people who were not involved, or at least not directly responsible. It's inevitable.
Nonetheless, you punish murderers with harsh justice system for two reasons:
1.) Because they are murderers; but also...
2.) To set an example to would-be criminals.
And you do this, even though you know that sometimes -- humans and human organizational systems being imperfect -- you're going to execute judgment on the innocent.
And war is messier by far than criminal justice. But - to take an example - even though the average Romanian worker was largely a hostage to Hitler's ambitions, once we were in that war, the oilfields of Ploesti still had to be bombed.
That said, Bin Laden is - like Saddam himself - largely a creature of US Interventionist "blowback".
Will we learn? I don't lay good odds on it.