The decisions taken by Mr Bush in the immediate aftermath of that ghastly moment will be pored over by historians for the rest of our lifetimes. One thing they will doubtless conclude is that the measures he took to lock down America's borders, scrutinise travellers to and from the United States, eavesdrop upon terrorist suspects, work closely with international intelligence agencies and take the war to the enemy has foiled dozens, perhaps scores of would-be murderous attacks on America. There are Americans alive today who would not be if it had not been for the passing of the Patriot Act. There are 3,000 people who would have died in the August 2005 airline conspiracy if it had not been for the superb inter-agency co-operation demanded by Bush

after 9/11.