- We can't win the war in six months, but we can lose it in six months.
- The troops have a job to do, and we shouldn't leave until the job is done.
- Setting a time table for withdrawal would insure defeat.
I suspect it's because they can't. If they try to set clear objectives, then any idiot can see that they're not achievable, that "victory" so defined is impossible.
And this just leads me to the conclusion that the "War on Terror" is one that the architects have no interest in winning; it's just the fighting that they care about, and the fighting never stops.