Watching Cameron dither about migrants has been deeply embarrassing. Other national leaders make a moral stand, argue from economic necessity or look for some kind of international collaboration. He does none of these. He reacts on impulse, watches the public reaction, and then changes his mind, from tough to compassionate to totally wet. And at no time does he seem to seriously grasp what's involved, and what's driving this huge movement of people. It's all about him, sending messages, not indulging people who are weak or misguided, as though he's been appointed to decide how the world should be organised. I dread to think how we must look to people in other countries.