How can the same thing happen to the same guy twice?

In his news conference today, George Bush argued for letting his commander in Iraq, David Petraeus, determine the US troops level in Iraq -- the rationale being that the military commanders make the best decisions. He then went on to float the possibility that his commanders were wrong about troop levels for the invasion itself in 2003 --

I mean, one of the questions is, should we have sent more in the beginning? Well, I asked that question, do you need more, to General Tommy Franks. In the first phase of this operation, General Franks was obviously in charge, and during our discussions in the run up to the decision to remove Saddam Hussein after he ignored the Security Council resolutions. My primary question to General Franks was, do you have what it takes to succeed? And do you have what it takes to succeed after you succeed in removing Saddam Hussein? And his answer was, yes.

Now, history is going to look back to determine whether or not there might have been a different decision made. But at the time, the only thing I can tell you, Wendell [Goler, Fox News], is that I relied upon our military commander to make the proper decision about troop strength. And I can remember a meeting with the Joint Chiefs, who said, we've reviewed the plan. I remember -- and seemed satisfied with it. I remember sitting in the PEOC, or the Situation Room, downstairs here at the White House, and I went to commander and commander that were all responsible of different aspects of the operation to remove Saddam. I said to each one of them, do you have what it takes? Are you satisfied with the strategy? And the answer was, yes.

Whether they wrong then is surely not just a matter for "history" but for whether they can be trusted now.