You could call it tea and crumpets if you wanted. In alot of ways, it's comparing apples to apples. There is a reason the US has not officially gone to "war" in years. The main goal in war is to completely eliminate your enemy, which was not the goal in Vietnam. I agree that Politicians tried to run the war who had no idea of the tenacity of the Vietcong whom their troops were up against. Still, you can't tell me that some of the greatest military minds at the time weren't doing their best to try and bring the Vietnam Conflict to an end. The Vietcong were willing to die in combat for their defense of Vietnam, while the average US soldier wasn't willing to do the same and give his life for a foreign country that did not appreciate his presence, which is completely understandable considering every soldier was assumed to be committing atrocities like those at Mai Lai.
The fact that America won every "major engagement" is a given, we had the clear military superiority but as history has show time and again, military superiority is not a sure fire way to win conflicts. Guerrilla warfare and the unbreakable spirit of a nation that had suffered through years of oppression is what lost America that war. Even if America had eventually settled Vietnam, it would have been at the cost of many more American lives, the proportion of kills to deaths would have been considered an even bigger military fiasco. The only way to truly settle the country would have been to nuke it completely, something no war historian would have considered a victory.
Bringing order to Vietnam would have cost thousands more lives and millions of dollars over the course of many years before we would have seen any kind of solid or progress being made. The costs would have greatly outweighed the benefits(the major benefit being the "containment" of communism). That and massive lack of home support and morale is why we left Vietnam. It would have been more similar to you beating up a kid, only to have him continuously and ferociously get up every time you knocked him down until the point of you getting so tired and worn out that you walked away from the fight.
http://www.youtube.com/watch?v=yHjSHGqTBxM