Among other things, Belmont Club makes the mathematical case for why large terrorist networks need state sponsors:

[This] is crucial to understanding why the defeat of the Taliban in Afghanistan and the toppling of Saddam Hussein may have cripped global terrorism so badly. Without the infrastrastructure of a state sponsor, terrorism is limited to cells of about 100 members in size in order to maintain security. In the context of the current campaign in Iraq, the strategic importance of places like Falluja or "holy places" is that their enclave nature allows terrorists to grow out their networks to a larger and more potent size. Without those sanctuaries, they would be small, clandestine hunted bands.

Which would provide ample justification for invading Iraq if, you know, there had been any large terrorist networks sheltered by Saddam Hussein to begin with. So let the hunt begin! By Belmont's specs, we are looking for a large terrorist organization of over 100 members, operating under Saddam Hussein.

Well okay, technically, if we want to say that invading Iraq has made us "safer" than before, we need to find more 100+ member groups under Hussein than exist in post-Hussein enclaves like Fallujah. But for now, all we ask for is a 100+ member group that could not have existed without Saddam Hussein. Thank you.