It wasn't bailing out of Vietnam that was a blunder. The blunder was in getting into Vietnam as a police action, not a war, with no clear objective (how do you know when you've succeeded?), and no clear exit strategy. A lot like W's war in Iraq.

Getting the Iraqi military and civil police to do the job ought to be recognized as maybe being on the list of things not necessarily possible for the US to do. It simply ain't possible to get someone else to do what you think they ought to do for their own good. The cultural anomoly of using our yardstick of success to measure what another culture ought to do is as stupid as it gets.

W is stupid, but Cheney isn't. There is no clear exit strategy because there is no intent to exit. Cheney doesn't leave oil.