There were lamentable failures in the subsequent US occupation, which allowed the rise of the hideous sectarian violence that threatened to tear the country to pieces. But in the last two years the “surge” of US troops under General David Petraeus appears to have destroyed much of the terrorists’ infrastructure and support. Now, as US troops begin their phased withdrawal, the new American-trained Iraqi army is defending the country against Islamist violence. There will be further setbacks. But who knows, Iraq may yet even become a model for democratic change in other Arab countries. If so, who deserves some credit? The much maligned President Bush. And Tony Blair.