According to presidential advisor Karl Rove, the head of the Secret Service detail “Eddie Marinzel later remembered Bush’s first words when he entered the cabin [on Air Force One on September 11, 2001] were ‘Gentlemen, we’re at war.’ I [Rove] knew we were before Bush uttered those words; but hearing those words said by the president of the United States was still chilling. The president then went on to say he hoped the American people understood it would be a different kind of war against an enemy unlike any we’d ever faced. It was likely to be a long struggle with years before victory, he said. As he later recalled, he realized on Air Force One this was a ‘defining moment in the history of the United States. I didn’t need any legal briefs. I didn’t need any consultations. I knew we were at war.’ ”
– Karl Rove, Courage and Consequence, Pages 256-257