ChrTh said:
The reason that I personally don't buy the "the US lost" emphasis is because it's pretty damn obvious to most people that winning was extremely unlikely. It's not like the Civil War, where Southerners can obsess over Lost Orders wrapped around Cigars or the first night at Gettysburg. It's not the losing part that makes Vietnam so pervasive, it's the whole sad uselessness of it all.
Harry G. Summers Jr.'s book
On Strategy discusses one reason why the U.S. lost the Vietnam War. Summers points out that the North Vietnamese had a clear, specific goal in the war, while the U.S. did not. Summers, who was a colonel in the Four Party Joint Military Commission overseeing the exchange of POWs at the end of the war, had a discussion with an NVA colonel:
Col. Summers: "You never defeated us on the field of battle."
Col. Tran: "This is probably true, it is also irrelevant."
Vietnam was the first war the U.S. lost. Well, that wasn't exactly the case. U.S. forces were not beaten on the battlefield, they were withdrawn. It was actually the first war the U.S. refused to win. The price of victory was considered higher than it was worth.
America lacked the will to win, to see it out to the end. This had never happened before and there was a reluctance on the part of the government to admit this was where it was all going. American politicians allowed more and more U.S. troops into Vietnam because it was easier to do that than to draw the line and demand that prowar partisans consider the implications of increased involvement. No one wanted to risk a small failure in the short term because, as politicans see it, long term problems will be someone else's responsibility. The troops and the voters slowly came to realize the mess they had gotten into and there were bad feelings all around as a result.
The American Civil War caused a division in public opinion over the wisdom of the war, as did several other wars (1812, Mexican, Spanish, Philippine Insurrection, and Korea), leading to social unrest and violence. But nothing like what was seen during Vietnam. The nation was truly divided and when it was clear that unified support for the war would never be achieved, the practical result was no support at all. One president refused to run for reelection because of the lack of popular support for the war, and another was elected on the promise of getting the U.S. out of Vietnam.
We didn't keep sending more and more troops to the front until victory was won, and then send everyone home to victory parades and civilian life. In Vietnam troops were constantly being transferred in and out of country just like it was another assignment. Even when it was decided to end our participation in the war, the troops came home gradually. And there weren't many parades.