At this point, Bush is almost admitting to being a failure. Without actually saying that, of course.
Loo at the shifting justifications:
The original case for supporting him in Iraq was the claim that they had WMD.
There were none.
So then it changed. We were ACTUALLY there to bring "liberation and democracy."
But that, too, now seems very unlikely.
So what is Bush's justification for our being there now?
He says there will be dire consequences if we fail.
In other words, Bush now claims that he is one best equipped to protect us from the consequences of his own misguided actions.
Strip away all the rhetoric, and that's the argument: "I am the one who can best avoid the disaster that would the natural end result of my policy."