A reader writes:

Your reader wrote: "What if 9/11 had been a nuclear attack?"

'What if,' indeed. On the first page of his excellent and disturbing book, "Nuclear Terrorism - The Ultimate Preventable Catastrophe" - Graham Allison, a former deputy secretary of defense under Clinton (and no fan of the Bush administration), relays the following anecdote:

On October 11, 2001, a month to the day after the terrorist assault on the World Trade Center and the Pentagon, President George W Bush faced an even more terrifying prospect. At that morning's Presidential Daily Intelligence Briefing, George Tenet, the director of central intelligence, informed the president that a CIA agent code-named Dragonfire had reported that Al Qaeda terrorists possessed a ten-kiloton nuclear bomb, evidently stolen from the Russian arsenal. According to Dragonfire, this nuclear weapon was now on American soil, in New York City.

Think about it. A month after 9-11, you are president Bush.

You are still struggling to get to grips with the 9/11 attacks when you are told that the same people who have just destroyed twin towers have a nuclear weapon in New York city. What do you do? How do you defend the country?

A big scare like this is, to me, the only reasonable explanation of why Bush and his cadre of advisers have been so willing to push their response to the 9/11 attacks so far. Bush and his crew were - and remain - scared shitless. They are terrified that the next report won't be a false alarm, and this fear informs every decision, every cost-benefit analysis they make. Don't get me wrong, I believe many of the steps taken by the Bush administration have been badly misguided, and are likely to harm US interests in the long run. If Allison's anecdote is true, it doesn't excuse the Bush administration's many bad decisions and policies, but it does go a long way towards explaining them.