The ICC is a court with complementary jurisdiction; it was conceived to take action where national courts couldn’t. Without too much detail, this means that legally, if the U.S. captures Osama bin Laden and wants to put him on trial, they have a right to. Even if someone else captures Osama bin Laden and handed him to the ICC, if it existed, the U.S. would still have the right to have first crack at him. So, you would need all the countries that have jurisdiction to agree to let the ICC keep him. And none of this, of course, answers the question how you could actually bring bin Laden or others to trial.
That‘s the biggest obstacle to using global justice against al Qaeda.
It’s just not so easy. One of the controversies people talk about relating to September 11th is whether you employ a law enforcement or military approach. In countries where a law-enforcement approach is possible, then that makes sense. But that‘s not possible in Afghanistan. Talking about the ICC, or any other instrument of international justice, is not like waving a magic wand. And it certainly doesn’t help you capture these people or actually bring them to justice.