I am a software developer in the US with a Vietnamese origin, so I am no historian and my views are probably skewed.
I am among the minority Northern Vietnamese people in the US, most Vietnamese people in the Bay Area are (refugees) from the South. People can tell where one comes from with one's accent. It was undeniable that much suffering and injustice was done for Southern people, especially after the war ended. So many still have a lot of resentments against the Hanoi government in particular and people from the North in general. Some still secretly view Northen international students in the US as red princes and princesses. The truth is far from that, they are just ordinary people looking for a better life. Many of the Northern people also have resentments with the current government as much as anyone else. However, I have to say much of the suffering and conflict is fading. I am so glad that in the last three years I was in the Bay Area, I have made many new Vietnamese friends, and have gone to many Vietnamese-owned shops buying groceries. I have not once had bad experiences with anyone in here. We spoke to each other and caring about each other despite of the differences.
When I was a student in the US, I borrowed as many books and DVDs about the Vietnam war I could from the library and began watching to understand where I came from, and what to make of the war. I am still searching for the answer. One thing I began to understand is the reason that the North won the war. The people from the North did have a charismatic leader and more importantly, they had a sense of righteousness and revenge when they participated in the war. I still remember vividly, one day I watched an (American) documentary about a farmer after the 1972 bombing operation. The bomb killed all of his family members and all the pigs he raised and left him with nothing. He cried and vowed to fight till he dies. The guy had lost everything, he had nothing left to lose. That was the moment I realized it was inevitable that the North would inevitably win.
I see that pattern a lot in places that talked about the war, for example in the article:
>She was only 24 years old but had been widowed twice. Both her husbands were soldiers. I saw her as the embodiment of the ideal guerrilla woman, who’d made great sacrifices for her country.
I do not have as much exposure (or at least as much as I wished) to the literature, arts, and music of the South, but I can say that the sense of righteousness while fighting wasn't as strong in places that I have looked into.
My (personal and flawed) conclusion is that it wasn't the policy, the brainwashing, or the political power of communism, or the help of Russia that made the North win. They won despite despite being poor as hell, they won despite being communist, and they won despite having lost more troops. They won because they took part in the war with a sense of righteousness.
By chance, I just revisited the Vietnam war and the scar it left a couple of days ago, how much it matters in my everyday life, and wrote an essay about it on my blog. Here is the blog I wrote a couple of days ago about the war, btw, if you're so interested: http://www.tnhh.net/posts/lullaby-of-the-artillery.html