Yes.
I simply can tell when the witness is not responding to the question. My last question, for example, was whether it's not a fact that there is no other developed country in the world that has indicated a willingness to bear the economic costs at 3.2% GDP. If the witness knows of another such country, I'd be happy to hear him tell me that, but if he's going to go off and take my precious seven minutes somewhere else, I think I have a right to interrupt.