No, the analogy is false.
To paraphrase Christopher Hitchens, there could not be a greater difference between a war fought with weapons of indiscriminate slaughter by a conscript Army deployed against a highly evolved revolutionary movement, as Vietnam, and a campaign by all-volunteer Army directed at the overthrow of a hideous and dangerous tyranny, and then taking the form of a drive for free elections and a constitution, as in Iraq.
In Iraq we are pursuing and killing people who really are, unlike the Viet Cong, the common enemies of humanity. These are people who have every intention of carrying forward a war against western civilization, if not in Iraq, at the next available opportunity.
There is another difference. Vietnam was a liberal war, waged by democrats, ended by a republican. Iraq, however, either for good or ill, will be laid at the doorstep of republicans.
For more on this fallacious analogy.
http://www.slate.com/id/2098642