It's about Iraq - so what?

And then there's the problem of saying that an effort isn't worthwhile if murderers oppose it. Nobody ever says it's not worth prosecuting the mob after mobsters murder policemen or judges in an attempt to intimidate them. And yet, even Blair is buying into the argument that if it were true that the London bombings were the result of the Iraq invasion, then the Iraq invasion would have been wrong. By this logic, it was wrong to declare war on Hitler because of the Blitz.