I agree about not knowing the outcome, but if my recollection is correct Mr. Bush, Cheney et al.(the majority of which had avoided service in Viet Nam) were dead certain:
1. The war would pay for itself.
2. We would be welcomed as liberators
3. There were weapons of mass destruction, mushroom clouds, etc.
4. It would be a "slam dunk" victory
5. We only needed a small number of troops
6. We'd be out in short order

If they had told the American people up front that we could be there for many, many years, maybe cost thousands of lives and casualties and billions of dollars, I don't think they would have had a chance in hell of getting approval particularly from fiscal conservatives. I don't want our politicians sending our brave troops into harm's way if they are not being up front with the American people and unless it is absolutely necessary.