Watching the news scroll in from Mumbai today, and seeing the death toll rise, and it occurs to me: this is not a sophisticated attack. It does not require complicated actions like making bombs or seizing aircraft. All it needs is a few Kalashnikovs, a pile of ammunition, and a group of people willing to die - terrorism on the cheap. It will be as effective at terrorising its victims as other, more complex plans - possibly more so because of its sheer randomness - and short of turning every city into a permanent armed camp, there is absolutely nothing any government can do about it. We are essentially helpless. And killing more people in Afghanistan or Pakistan or Somalia or wherever they're bombing this week won't stop that - rather, it will increase the risk, by providing more outrages to make people willing to die.