Remember when you guys kept telling us "everything's changed" after 9/11?
The implemented policy ramifications of the changed universe were what came to be known as the Bush doctrine. One important aspect was the withheld right to unilaterally invade a foreign country if we had any suspicion that they harbored terrorists or had or were developing (or might develop) WMDs. I think that's what most people think of. It is what I think of.
Certainly, when I hear the phrase "Bush Doctrine" I do not respond with a "duh".