All the (US-targeted) guide books on Vietnam include some variant of the question, "Will I face harassment or hostility because I am an American (due to the war)?" The answer is always no. Officially, the reason is because Vietnam now espouses a foreign policy of "friend to all" and furthermore is trying to strengthen its partnership with the U.S. in order to gain economically and hedge against China. But I'll always remember a video I watched in an undergrad class on Modern Southeast Asia years ago, where an old Vietnamese woman is asked if she resents Americans and she replies, "Why would I? We won!"
Politically, Communism (socialism) hasn't gone away. It's still official state policy. But Vietnam is showing a lot of market economy tendency these days, which means the hammer-and-sickle has become a marketing tool. Along with the yellow (or red) star that shows up on the Vietnamese flag, tourists can buy t-shirts, baseball caps, and beer koozies with the hammer-and-sickle or Ho Chi Minh's face. If you get one of the military hats you can even pretend you're a Vietnamese soldier!
The American Consulate in Ho Chi Minh City plays up the tortured history of the Consulate - "there's the wall where the Viet Cong broke in," the economic officer said, "This is a replica of the plaque that we had before they broke in. We don't know where the original is. Probably in a warehouse somewhere." But from Vietnam's standpoint I've actually seen very little dwelling on "the war," except when it's used to sell merchandise - and then it seems to be more about catering to Americans' pre-existing image of Vietnam than anything else. Maybe they figure Westerners can't imagine coming to this place that to them means war and a whole generation of reflective movies about what was seen as a tragedy of the American spirit without getting some kind of knick-knack that speaks to this period, some recognition that yes, this war really happened and it wasn't some other tropical backwater we were thinking of.
Because otherwise you won't look around Vietnam and see any vestiges of war (especially if you avoid Agent Orange "hotspots" like the one at Danang Airport). It's a modernizing country with plenty of tourists, humidity, street vendors, motorbikes, rice noodles. In Hanoi you see giant old buildings with colonial architecture but that's almost to be expected in Southeast Asia. As someone who grew up listening to protest songs and watching Apocalypse Now, I won't deny that it's a little odd. So you can get a bag that says "Good Morning Viet Nam," and one chain store in Hanoi is called Old Propaganda Posters. I must admit I succumbed to the latter. But in my defense, it's a nice poster.