I appreciate that and I'm sorry if I was going too much on purposes. We tried to say coerce X to do Y, constrain X from doing Y, signal X about the violation of the norm. That's only the first step. The second step is to ask what happened. There may be evidence that al Qaeda was constrained. We can determine that on a five-point scale, from no effect whatsoever to strong evidence of constraint being number five.
A separate question altogether is what the effects of sanctions are on that outcome. What we do is we first look at all the other policy instruments, just as you've identified them. Was there a threat of force? Was there the use of force? Were there covert actions? Were there other sanctions in place? Most important, were there acts of mediation or negotiations under way? We look at everything else going on before we try to assess whether sanctions made a modest, major, or significant contribution to the outcome. That's how we evaluate.
We also ask ourselves what we call a counterfactual question which is a simple “what if”: what if there had been no sanctions? We try to go through an exercise systematically. We do that for every single episode, all three purposes, and we publish the rationale. We don't just give a number, we actually say why we gave it that number. So we're trying to be transparent. That's how we do it.