What good does that do? For example, we fought a war to keep Vietnam free and democratic and failed miserably. The Communist regime only began to make meaningful change once we opened up to them.

First, I agree with your sentiment. Cuba is an excellent example of this. It's one of the last Communist holdouts, and one of the few Communist countries we refused to open up to. Coincidence? I think not.

However, when it came to Vietnam, we merely fought a war to keep Vietnam on our side. South Vietnam was not free and democratic, so there was impossible to "keep" it that way.

It's possible, maybe even likely, that a victorious South Vietnam would have eventually opened up and turned to democracy, as happened in South Korea and Taiwan. But I think it's important to recognize how two-faced US policy was in these places, fighting "for freedom" by propping up dictators.

US doesn't care about freedom in other countries. They may say so, but action say a bit different story - how can they be good friends with places like Saudi Arabia and worse? what they care about is, are you with us or against? any other position is very hard to maintain, albeit possible. you just need a bit extra finance for that.

freedom and good life for vietnamese people was not considered much when that war was planned (beginning by staged US Tonkin gulf accident to get a foot in situation, in good ol' Gleiwitz nazi style). it was all about influence, having foothold out there so soviets don't take it all around, keeping armed forces trained in real life scenarios (train your forces in small war to be prepared for big one) etc. US was very much anything but a good guy there. Saying North vietnamese did worse things doesn't make you automatically a good guy, does it.

Nah, Vietnam is just another topic in US history americans should feel ashamed of. Quite a few I met that are not teenagers actually do. And look at result - they lost the war, they screwed up that country really bad (ie many birth defects many years after the war thanx to Agent Orange spraying), and at the end, country found its way to +-democracy in peaceful way, although it took some serious time. But you can't make that much money from selling arms in peace, can you