The Commodious Ambiguity of “Optimism”

[I seem to be working my way back into rambling Philosophy mode here.]
General Abizaid said: “So the question is, am I optimistic whether or not Iraqi forces, with our support, with the backing of the Iraqi government, can prevent the slide to civil war? My answer is yes, I’m optimistic that that slide can be prevented.” NYT
This is subtle. My guess is he was actively trading on a systematic ambiguity about optimism.
Why? Today’s generals really do operate under a serious, post-Vietnam, military compunction. It is strongly felt within the services that the Vietnam generals sold out the troops when they lied about the prospects of that war.
The ambiguity:
Why does he introduce and lean on optimism?
On returning from a tour of the situation, you might say “I am optimistic about our prospects,” and that would indicate your conviction that what you saw gave you good reason to be hopeful.
But you also might say “I am optimistic” because you had a big glass of Happy Juice on the flight back, and it made you optimistic about everything. Nonetheless, you were truthful when you expressed your optimism.
The general could have been thinking that his job as a military leader is to be optimistic. So saying he is optimistic does not really render his strategic opinion; it just reports an optimistic state of mind. He is supposed to be optimistic.
Now absent the Happy Juice, the mental state he is reporting does not exist. So the report is a deception–but only a dutiful, understandable, expected, pro forma deception. In contrast, if he’d said, “I believe that the slide is likely to be prevented,” instead of merely “I’m optimistic that the slide can be prevented,” it would have been bald deception.