And one other thought...
...the main lesson that the military got from Vietnam is that before using force, you better (a) clearly define the objectives; (b) establish a "military" plan for achieving those objectives; (c) not place constraints on the military that prevents it from doing it's job.
One thing that I notice is that we've got some heavy duty constraints on our military in Iraq: (1) Try and keep civilian casualties to a bare minimum; (2) Don't piss of the natives; (3) save the oilfields; (4) Save the infrastructure; (5) minimize American casualties; (6) Do all this within a very, very, very short amount of time; (7). Keep the scuds/missles from being launched at the neighbors in Kuwait, Saudi, and Israel.
There's probably some additional constraints that I'm not thinking of. A lot of these constraints are also based on Political objectives - not Military. Which is probably where I'd draw more of a parallel with Vietnam. Practically every military objective was accomplished in Vietnam. The problem was that not one of the political objectives was met.
